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Table of contents

1. Top 100 large numbers factored by SNFS
2. Top 100 large numbers factored by GNFS
3. Top 100 large factors found by NFS
4. Large factors found by ECM
5. Nice split
6. Unprovable near-repdigit PRPs
7. Unprovable quasi-repdigit PRPs
8. Quasi-repdigit twin primes

1. Top 100 large numbers factored by SNFS

	digits	composite number	prime factors	from	when	who
1	229		P95 · P134	(73·10228-1)/9	Oct 27, 2009	Robert Backstrom
2	224		P50 · P85 · P89	10225+3	Oct 12, 2009	Robert Backstrom
3	223		P70 · P74 · P80	8·10230-1	Aug 31, 2009	Markus Tervooren
4	222		P101 · P122	(10229-7)/3	Nov 19, 2009	Robert Backstrom
5	222		P55 · P55 · P114	(25·10223-1)/3	Nov 7, 2008	Serge Batalov
6	222		P51 · P51 · P120	(10222+17)/9	Jul 9, 2009	Dmitry Domanov
7	220		P74 · P147	(16·10221-61)/9	Aug 28, 2009	Robert Backstrom
8	218		P54 · P165	4·10217-9	Jun 27, 2009	Robert Backstrom
9	216		P77 · P139	4·10219-9	May 1, 2009	Robert Backstrom
10	213		P49 · P165	2·10220-1	Jul 18, 2009	Robert Backstrom
11	212		P87 · P125	2·10216-1	Jul 5, 2009	Robert Backstrom
12	211		P46 · P61 · P106	2·10212-1	Jul 24, 2009	Robert Backstrom
13	211		P82 · P130	(16·10217-7)/9	Nov 3, 2009	Lionel Debroux
14	211		P57 · P154	4·10217+1	Apr 17, 2009	Robert Backstrom
15	211		P47 · P165	(25·10215-1)/3	Aug 13, 2009	Robert Backstrom
16	211		P57 · P154	(64·10321-1)/9	Apr 8, 2009	Robert Backstrom
17	211		P63 · P72 · P76	(8·10220+7)/3	Nov 5, 2009	Robert Backstrom
18	210		P40 · P57 · P114	4·10213+9	Aug 4, 2009	Robert Backstrom
19	209		P53 · P156	10212+3	Aug 18, 2009	Robert Backstrom
20	208		P100 · P108	4·10209+1	Feb 17, 2009	Serge Batalov
21	207		P60 · P148	(10211+53)/9	Mar 20, 2009	Serge Batalov
22	207		P88 · P119	(2·10209+1)/3	Jul 27, 2009	Robert Backstrom
23	206		P50 · P157	(19·10205-7)/3	Jun 9, 2009	Wataru Sakai
24	206		P67 · P139	(16·10205-1)/3	Nov 10, 2008	Robert Backstrom
25	206		P103 · P104	(14·10205-11)/3	Feb 22, 2009	Wataru Sakai
26	206		P53 · P75 · P79	(37·10205+17)/9	Feb 26, 2009	Robert Backstrom
27	206		P68 · P139	(25·10205-43)/9	Nov 20, 2008	Robert Backstrom
28	206		P58 · P148	(7·10207-43)/9	Jun 16, 2009	Robert Backstrom
29	205		P100 · P106	(4·10207-1)/3	Jul 19, 2008	Serge Batalov
30	205		P51 · P73 · P82	(64·10211-1)/9	Jun 10, 2009	Robert Backstrom
31	205		P48 · P71 · P88	(11·10204-17)/3	Dec 16, 2008	Robert Backstrom
32	205		P102 · P103	(37·10204+17)/9	Feb 5, 2009	Robert Backstrom
33	204		P50 · P155	(2·10205+1)/3	Aug 25, 2009	Dmitry Domanov
34	204		P52 · P153	(52·10204+11)/9	Jun 17, 2009	Markus Tervooren
35	204		P56 · P149	(47·10204+7)/9	Mar 24, 2009	Robert Backstrom
36	204		P79 · P126	(13·10203+17)/3	Feb 8, 2009	Wataru Sakai
37	204		P66 · P138	(64·10203-1)/9	Nov 4, 2008	Robert Backstrom
38	204		P60 · P144	(56·10203+43)/9	Jul 23, 2009	Dmitry Domanov
39	204		P40 · P164	(38·10203+61)/9	Jan 26, 2009	Wataru Sakai
40	203		P54 · P67 · P83	(10207+17)/9	Mar 30, 2009	Robert Backstrom
41	203		P42 · P59 · P102	(53·10203-17)/9	Jun 2, 2009	Robert Backstrom
42	203		P93 · P110	(41·10203+31)/9	Feb 20, 2009	Robert Backstrom
43	202		P80 · P123	(22·10203+41)/9	Sep 10, 2008	Serge Batalov
44	202		P43 · P160	(41·10205-23)/9	Oct 13, 2009	matsui
45	202		P60 · P143	(56·10202+43)/9	Jun 28, 2009	Dmitry Domanov
46	202		P62 · P69 · P72	(7·10205-43)/9	Aug 26, 2009	Wataru Sakai
47	202		P58 · P144	(44·10202-17)/9	Mar 10, 2009	Robert Backstrom
48	202		P86 · P117	(41·10203-23)/9	Mar 16, 2009	Robert Backstrom
49	202		P65 · P138	(44·10204+1)/9	Oct 3, 2009	Robert Backstrom
50	202		P47 · P55 · P100	(35·10202-17)/9	Mar 5, 2009	Robert Backstrom
51	201		P77 · P125	(79·10200-7)/9	Dec 25, 2006	Alexander Mkrtychyan
52	201		P50 · P152	(55·10205+71)/9	Oct 1, 2009	Wataru Sakai
53	201		P91 · P111	(43·10200+11)/9	Aug 9, 2009	Jo Yeong Uk
54	201		P62 · P139	(49·10202-31)/9	Sep 30, 2009	Robert Backstrom
55	201		P53 · P70 · P79	(22·10200-31)/9	Aug 1, 2008	Serge Batalov
56	201		P37 · P41 · P123	(52·10200+11)/9	May 28, 2009	Wataru Sakai
57	200		P73 · P128	4·10203+1	May 8, 2009	Wataru Sakai
58	200		P47 · P62 · P92	(32·10204-41)/9	Dec 7, 2008	Robert Backstrom
59	200		P41 · P76 · P84	(46·10202+17)/9	Jun 11, 2009	matsui
60	200		P84 · P116	6·10200+1	Jul 4, 2008	Serge Batalov
61	200		P52 · P65 · P84	(14·10200-23)/9	Oct 30, 2008	Robert Backstrom
62	200		P60 · P67 · P73	(56·10200+61)/9	May 28, 2009	Robert Backstrom
63	200		P56 · P61 · P84	(56·10201+61)/9	Sep 27, 2009	Robert Backstrom
64	199		P54 · P73 · P74	(7·10199-61)/9	Nov 23, 2008	Wataru Sakai
65	199		P61 · P138	(2·10199-17)/3	Aug 31, 2008	Wataru Sakai
66	199		P52 · P148	(53·10198-17)/9	May 16, 2009	Jo Yeong Uk
67	199		P34 · P80 · P86	(29·10198+61)/9	Nov 30, 2008	Wataru Sakai
68	199		P82 · P118	3·10198+1	Sep 8, 2008	Serge Batalov
69	199		P48 · P69 · P83	(23·10198-41)/9	Nov 14, 2008	Wataru Sakai
70	199		P46 · P154	(7·10200+11)/9	Apr 25, 2009	Wataru Sakai
71	199		P90 · P110	(5·10198-17)/3	Dec 1, 2008	Jo Yeong Uk
72	199		P60 · P66 · P74	(8·10199-17)/9	Dec 15, 2008	Wataru Sakai
73	199		P55 · P144	4·10200-3	Dec 6, 2008	Wataru Sakai
74	198		P89 · P110	(5·10200+13)/9	Aug 17, 2009	Ignacio Santos
75	198		P40 · P158	(28·10198+53)/9	Dec 28, 2008	Wataru Sakai
76	198		P87 · P112	4·10198+9	Feb 18, 2009	matsui
77	197		P54 · P144	(8·10197+1)/9	Nov 4, 2008	Wataru Sakai
78	197		P82 · P116	(35·10198+1)/9	Nov 6, 2009	Wataru Sakai
79	197		P96 · P102	(2·10197+1)/3	Nov 1, 2008	Wataru Sakai
80	197		P67 · P131	6·10196+1	Jul 21, 2008	Wataru Sakai
81	197		P52 · P146	(16·10197-7)/9	May 26, 2009	Dmitry Domanov
82	197		P76 · P122	(47·10196+61)/9	Apr 17, 2009	Jo Yeong Uk
83	197		P52 · P60 · P87	2·10200-3	Feb 14, 2009	matsui
84	197		P66 · P132	(41·10198+13)/9	Nov 16, 2009	Sinkiti Sibata
85	197		P57 · P66 · P74	(37·10196+53)/9	Dec 28, 2008	Wataru Sakai
86	197		P54 · P54 · P90	3·10196-1	Oct 3, 2008	Jo Yeong Uk
87	197		P78 · P119	(5·10197-11)/3	May 22, 2009	Robert Backstrom
88	197		P49 · P148	(32·10196+31)/9	Feb 12, 2009	Robert Backstrom
89	197		P73 · P124	(31·10196-13)/9	Feb 9, 2009	Robert Backstrom
90	196		P69 · P128	(67·10200+23)/9	Jul 24, 2009	Wataru Sakai
91	196		P60 · P136	4·10198+1	Mar 3, 2009	Wataru Sakai
92	196		P44 · P49 · P104	(13·10195+17)/3	Feb 13, 2009	Jo Yeong Uk
93	196		P63 · P134	(38·10195+61)/9	Jan 6, 2009	Wataru Sakai
94	196		P73 · P124	(37·10195+53)/9	Apr 4, 2009	Jo Yeong Uk
95	196		P80 · P117	(4·10199-7)/3	Aug 9, 2009	Wataru Sakai
96	196		P44 · P152	(49·10201+41)/9	Nov 6, 2009	Lionel Debroux
97	196		P88 · P108	(19·10196+71)/9	Jan 19, 2009	Wataru Sakai
98	196		P55 · P141	(64·10197-1)/9	Oct 23, 2008	Robert Backstrom
99	196		P87 · P109	(82·10198-1)/9	May 19, 2009	Robert Backstrom
100	196		P39 · P40 · P58 · P60	(23·10199-41)/9	Sep 6, 2009	Wataru Sakai

2. Top 100 large numbers factored by GNFS

	digits	composite number	prime factors	from	when	who
1	153		P41 · P55 · P57	9·10229-1	Nov 11, 2009	matsui
2	148		P63 · P85	(16·10220-61)/9	Dec 24, 2008	Serge Batalov
3	146		P56 · P91	(64·10333-1)/9	Oct 29, 2009	matsui
4	145		P52 · P93	4·10212+9	May 12, 2009	Markus Tervooren
5	144		P70 · P74	(64·10232+53)/9	Aug 13, 2008	Serge Batalov
6	142		P70 · P73	8·10233-1	Oct 21, 2009	matsui
7	140		P53 · P88	(16·10214-61)/9	Aug 4, 2008	Serge Batalov
8	140		P49 · P92	(26·10203+1)/9	Jun 11, 2009	Dmitry Domanov
9	140		P45 · P95	4·10200+7	Mar 6, 2008	Tyler Cadigan
10	139		P60 · P79	6·10199+1	Jul 10, 2008	Tyler Cadigan
11	138		P60 · P79	(10196+53)/9	Feb 25, 2009	Tyler Cadigan
12	138		P62 · P77	2·10200+9	Nov 1, 2009	Dmitry Domanov
13	138		P49 · P89	(10198+53)/9	Aug 1, 2008	Tyler Cadigan
14	138		P64 · P74	(7·10196-43)/9	May 9, 2008	Wataru Sakai
15	137		P49 · P88	(55·10199+53)/9	Jun 5, 2009	Sinkiti Sibata
16	137		P46 · P92	(16·10202-7)/9	Aug 31, 2009	Dmitry Domanov
17	137		P47 · P91	2·10207-1	Jun 17, 2009	Andreas Tete
18	136		P59 · P78	9·10249-1	May 29, 2009	matsui
19	136		P67 · P69	10194+3	Sep 26, 2009	Tyler Cadigan
20	135		P49 · P86	(4·10195-1)/3	Nov 17, 2007	Jo Yeong Uk
21	135		P54 · P81	(16·10232-7)/9	Sep 4, 2009	Dmitry Domanov
22	134		P47 · P88	8·10190-1	May 28, 2008	Jo Yeong Uk
23	134		P50 · P84	8·10193-9	May 23, 2009	Sinkiti Sibata
24	133		P43 · P91	(2·10200+61)/9	May 15, 2009	Sinkiti Sibata
25	133		P45 · P88	(25·10190-7)/9	Mar 26, 2009	Andreas Tete
26	132		P51 · P81	6·10194+1	Apr 27, 2009	Tyler Cadigan
27	131		P56 · P76	2·10193+9	Jul 22, 2009	Dmitry Domanov
28	131		P60 · P72	(22·10186-31)/9	Jul 29, 2008	Sinkiti Sibata
29	131		P44 · P87	(52·10188+11)/9	Apr 21, 2009	Andreas Tete
30	130		P59 · P72	2·10195+9	Oct 18, 2009	Dmitry Domanov
31	130		P46 · P84	(4·10203-1)/3	May 5, 2009	Sinkiti Sibata
32	130		P60 · P70	(85·10186+41)/9	Feb 15, 2009	Erik Branger
33	129		P61 · P69	3·10191+1	Jul 3, 2008	matsui
34	128		P46 · P83	4·10187-9	Nov 11, 2008	Sinkiti Sibata
35	128		P63 · P66	2·10191+3	May 7, 2009	Ignacio Santos
36	127		P39 · P89	8·10187-1	Apr 24, 2008	Jo Yeong Uk
37	127		P43 · P84	(73·10191-1)/9	May 6, 2009	Ignacio Santos
38	126		P60 · P67	(64·10309-1)/9	Feb 16, 2009	Wataru Sakai
39	126		P44 · P82	(4·10241-1)/3	Mar 25, 2009	Ignacio Santos
40	126		P50 · P76	(16·10182-7)/9	Apr 22, 2008	Wataru Sakai
41	126		P55 · P71	(5·10185-23)/9	Aug 10, 2008	Serge Batalov
42	126		P52 · P74	(8·10184+7)/3	Jul 31, 2009	Justin Card
43	125		P57 · P68	(49·10181+23)/9	May 4, 2009	Ignacio Santos
44	125		P56 · P70	4·10199+9	Feb 20, 2009	Erik Branger
45	125		P58 · P68	(31·10168+41)/9	Mar 9, 2009	Andreas Tete
46	125		P49 · P76	(16·10189-7)/9	May 26, 2009	Dmitry Domanov
47	125		P46 · P79	(10181+17)/9	Sep 30, 2008	Justin Card
48	125		P49 · P76	(10187+17)/9	Sep 9, 2009	Erik Branger
49	124		P60 · P65	(43·10203-7)/9	Oct 6, 2009	Lionel Debroux
50	124		P57 · P68	2·10177-3	May 17, 2009	Dmitry Domanov
51	124		P43 · P82	(35·10181-53)/9	Nov 19, 2008	Erik Branger
52	124		P61 · P63	6·10198+7	Oct 3, 2009	Erik Branger
53	124		P62 · P63	(19·10197+17)/9	Sep 30, 2009	Erik Branger
54	124		P59 · P65	(5·10198-11)/3	Aug 4, 2008	Tyler Cadigan
55	124		P62 · P63	8·10197+9	Jun 1, 2008	Tyler Cadigan
56	124		P62 · P63	10178+7	Sep 30, 2009	Sinkiti Sibata
57	124		P59 · P65	(5·10190+13)/9	May 30, 2008	Tyler Cadigan
58	124		P54 · P71	(25·10193-61)/9	Jul 29, 2009	Justin Card
59	124		P57 · P67	(53·10178+1)/9	Sep 21, 2009	Markus Tervooren
60	124		P55 · P69	(14·10173-17)/3	Oct 27, 2009	Robert Backstrom
61	124		P44 · P80	5·10193-3	Jul 23, 2009	Andreas Tete
62	124		P61 · P63	(35·10176-71)/9	Apr 23, 2009	Ignacio Santos
63	123		P59 · P65	3·10179-1	Feb 16, 2008	matsui
64	123		P53 · P71	6·10192+7	May 28, 2008	Tyler Cadigan
65	123		P51 · P72	(17·10179-11)/3	May 21, 2009	Sinkiti Sibata
66	123		P48 · P75	(29·10199-11)/9	Apr 1, 2009	Andreas Tete
67	123		P58 · P65	(59·10172-41)/9	Nov 18, 2009	Erik Branger
68	123		P49 · P75	(53·10179-17)/9	May 18, 2009	Erik Branger
69	123		P59 · P64	(16·10190-61)/9	Feb 12, 2008	Tyler Cadigan
70	123		P58 · P65	(25·10157+11)/9	Sep 22, 2008	Sinkiti Sibata
71	123		P50 · P73	(37·10194+71)/9	Apr 28, 2009	Ignacio Santos
72	122		P40 · P83	(8·10173-11)/3	Apr 22, 2009	Ignacio Santos
73	122		P41 · P82	(44·10200-53)/9	Apr 25, 2009	Sinkiti Sibata
74	122		P51 · P72	7·10187-9	May 12, 2009	Dmitry Domanov
75	122		P41 · P82	(26·10176-71)/9	Oct 1, 2008	Sinkiti Sibata
76	122		P39 · P41 · P43	(2·10188-17)/3	May 31, 2007	Sinkiti Sibata
77	122		P40 · P82	(49·10173-31)/9	Apr 21, 2009	Ignacio Santos
78	122		P39 · P84	(25·10173+11)/9	Apr 21, 2009	Ignacio Santos
79	122		P51 · P71	(52·10183+11)/9	Apr 20, 2009	Ignacio Santos
80	122		P54 · P68	(37·10186+17)/9	Apr 19, 2009	Ignacio Santos
81	122		P44 · P79	(32·10194+13)/9	Apr 18, 2009	Ignacio Santos
82	122		P55 · P67	(85·10185+41)/9	Aug 12, 2008	Serge Batalov
83	122		P45 · P77	(19·10176+53)/9	Aug 13, 2008	Serge Batalov
84	122		P61 · P62	5·10181-1	Oct 17, 2009	Sinkiti Sibata
85	122		P54 · P68	(59·10176-23)/9	Sep 17, 2009	Erik Branger
86	122		P46 · P76	(2·10178+61)/9	Mar 12, 2008	Robert Backstrom
87	122		P61 · P61	(8·10178-53)/9	Aug 12, 2008	Serge Batalov
88	122		P41 · P81	(49·10171-13)/9	Aug 29, 2009	Erik Branger
89	122		P51 · P71	5·10180-7	Jul 11, 2008	Sinkiti Sibata
90	122		P44 · P78	(28·10176+71)/9	Apr 17, 2009	Ignacio Santos
91	121		P33 · P45 · P45	(47·10187+61)/9	Apr 16, 2009	Ignacio Santos
92	121		P57 · P64	(37·10178+17)/9	Apr 16, 2009	Ignacio Santos
93	121		P54 · P68	5·10188+9	Apr 22, 2009	Sinkiti Sibata
94	121		P59 · P63	(43·10180+11)/9	Apr 15, 2009	Jeff Gilchrist
95	121		P56 · P66	(16·10199-43)/9	Aug 4, 2008	Serge Batalov
96	121		P44 · P78	(47·10182+61)/9	Apr 15, 2009	Jeff Gilchrist
97	121		P44 · P78	(43·10177-61)/9	Apr 14, 2009	Jeff Gilchrist
98	121		P38 · P84	8·10185+9	Nov 28, 2008	Serge Batalov
99	121		P50 · P71	(35·10190+1)/9	Feb 1, 2009	Ignacio Santos
100	121		P40 · P81	(55·10200+17)/9	May 3, 2009	Sinkiti Sibata

3. Top 100 large factors found by NFS

	digits	prime factor	from	when	who
1	103		(14·10205-11)/3	Feb 22, 2009	Wataru Sakai
2	102		(37·10204+17)/9	Feb 5, 2009	Robert Backstrom
3	101		(10229-7)/3	Nov 19, 2009	Robert Backstrom
4	100		(4·10207-1)/3	Jul 19, 2008	Serge Batalov
5	100		4·10209+1	Feb 17, 2009	Serge Batalov
6	97		6·10198+1	Mar 14, 2009	matsui
7	96		(2·10197+1)/3	Nov 1, 2008	Wataru Sakai
8	96		(25·10195-61)/9	Oct 8, 2008	Tyler Cadigan
9	95		(73·10228-1)/9	Oct 27, 2009	Robert Backstrom
10	95		(37·10193-1)/9	Aug 9, 2009	Wataru Sakai
11	94		(17·10192+1)/9	Aug 25, 2008	Robert Backstrom
12	93		(41·10203+31)/9	Feb 20, 2009	Robert Backstrom
13	93		(65·10189+43)/9	Oct 27, 2009	Wataru Sakai
14	92		(68·10192+13)/9	Sep 1, 2008	Robert Backstrom
15	91		(22·10198-1)/3	May 15, 2009	Robert Backstrom
16	91		(43·10200+11)/9	Aug 9, 2009	Jo Yeong Uk
17	90		(26·10183-17)/9	Oct 29, 2008	Jo Yeong Uk
18	90		(47·10191+7)/9	Jun 28, 2009	Wataru Sakai
19	90		(38·10193+43)/9	Jan 8, 2009	Jo Yeong Uk
20	90		(5·10198-17)/3	Dec 1, 2008	Jo Yeong Uk
21	90		(31·10183-13)/9	Jul 27, 2009	Robert Backstrom
22	89		(4·10190-31)/9	Nov 2, 2007	Jo Yeong Uk
23	89		(5·10200+13)/9	Aug 17, 2009	Ignacio Santos
24	89		(4·10192-13)/9	Feb 19, 2008	Jo Yeong Uk
25	89		9·10185+7	Nov 22, 2008	Wataru Sakai
26	89		(4·10188-31)/9	Oct 17, 2007	Jo Yeong Uk
27	88		(82·10185-1)/9	Jun 15, 2008	Robert Backstrom
28	88		(19·10196+71)/9	Jan 19, 2009	Wataru Sakai
29	88		5·10194+9	Sep 6, 2008	Jo Yeong Uk
30	88		(43·10182-61)/9	Jul 23, 2009	Robert Backstrom
31	88		(2·10209+1)/3	Jul 27, 2009	Robert Backstrom
32	88		(23·10198+31)/9	Sep 21, 2009	matsui
33	88		(5·10179-17)/3	Jul 9, 2007	Robert Backstrom
34	87		(10183+53)/9	Jan 23, 2009	Tyler Cadigan
35	87		(82·10198-1)/9	May 19, 2009	Robert Backstrom
36	87		2·10216-1	Jul 5, 2009	Robert Backstrom
37	87		(55·10182+71)/9	Aug 9, 2009	Wataru Sakai
38	87		(58·10198+23)/9	Sep 26, 2009	matsui
39	87		4·10198+9	Feb 18, 2009	matsui
40	86		4·10180+3	Jun 17, 2007	Sinkiti Sibata
41	86		(32·10190+31)/9	Jun 16, 2009	Wataru Sakai
42	86		(83·10190+7)/9	Nov 7, 2009	Sinkiti Sibata
43	86		(11·10181+43)/9	Mar 5, 2008	Jo Yeong Uk
44	86		(41·10203-23)/9	Mar 16, 2009	Robert Backstrom
45	85		10183+3	Mar 3, 2008	Robert Backstrom
46	85		10225+3	Oct 12, 2009	Robert Backstrom
47	85		(65·10178+7)/9	Nov 3, 2009	Dmitry Domanov
48	84		6·10192-1	Mar 16, 2009	matsui
49	84		(16·10181-61)/9	Sep 9, 2007	Robert Backstrom
50	84		(25·10181-43)/9	Sep 30, 2008	Robert Backstrom
51	84		(67·10173-31)/9	Nov 6, 2009	Dmitry Domanov
52	84		(8·10196+1)/9	Apr 27, 2009	Jo Yeong Uk
53	84		6·10200+1	Jul 4, 2008	Serge Batalov
54	84		(16·10218-7)/9	Nov 10, 2009	Lionel Debroux, Jeff Gilchrist
55	84		(52·10175+11)/9	Apr 18, 2009	Ignacio Santos
56	84		4·10183-9	Nov 12, 2008	Serge Batalov
57	84		(56·10190-11)/9	May 24, 2009	Robert Backstrom
58	84		(29·10184+43)/9	Dec 20, 2008	Robert Backstrom
59	83		(52·10180+11)/9	Apr 24, 2009	Ignacio Santos
60	83		(67·10175+23)/9	Oct 9, 2008	Jo Yeong Uk
61	83		(44·10180+1)/9	Mar 12, 2009	Sinkiti Sibata
62	83		(26·10170-53)/9	Oct 8, 2008	Serge Batalov
63	83		(62·10170-71)/9	Nov 15, 2009	Dmitry Domanov
64	83		(10192+53)/9	May 18, 2008	Wataru Sakai
65	83		(38·10186+61)/9	Jan 12, 2009	Sinkiti Sibata
66	82		(16·10217-7)/9	Nov 3, 2009	Lionel Debroux
67	82		(35·10198+1)/9	Nov 6, 2009	Wataru Sakai
68	82		(5·10171-23)/9	Oct 16, 2008	Robert Backstrom
69	82		(23·10188+13)/9	Nov 4, 2008	Wataru Sakai
70	82		(59·10184-41)/9	Sep 15, 2009	Ignacio Santos
71	82		(16·10177+11)/9	Sep 9, 2008	Robert Backstrom
72	82		(37·10173+17)/9	Dec 21, 2008	Jo Yeong Uk
73	82		3·10198+1	Sep 8, 2008	Serge Batalov
74	82		(17·10185-53)/9	Jun 3, 2008	Robert Backstrom
75	82		(14·10180+1)/3	Mar 28, 2009	Ignacio Santos
76	82		(23·10174+1)/3	Mar 1, 2007	Tyler Cadigan
77	81		(37·10167-1)/9	May 14, 2007	Robert Backstrom
78	81		(2·10185+1)/3	Aug 5, 2008	matsui
79	81		(85·10180+41)/9	Apr 26, 2009	Ignacio Santos
80	81		(52·10181-7)/9	Sep 20, 2007	Robert Backstrom
81	81		(67·10166+23)/9	Jan 12, 2008	Robert Backstrom
82	81		(2·10178+1)/3	Jul 17, 2008	Wataru Sakai
83	81		(59·10165+13)/9	Oct 28, 2009	Dmitry Domanov
84	81		8·10176+9	Feb 24, 2008	matsui
85	81		(43·10184-7)/9	Jan 6, 2009	Tyler Cadigan
86	80		(14·10182+1)/3	Jul 13, 2009	Robert Backstrom
87	80		6·10180+1	Jul 5, 2009	Tyler Cadigan
88	80		(5·10175+1)/3	Jun 15, 2008	Kenji Ibusuki
89	80		(29·10198+61)/9	Nov 30, 2008	Wataru Sakai
90	80		(19·10175+71)/9	Jun 18, 2008	Jo Yeong Uk
91	80		(13·10171-1)/3	Jun 7, 2007	Robert Backstrom
92	80		(5·10174-17)/3	Oct 1, 2009	Ignacio Santos
93	80		(22·10191-1)/3	Jul 24, 2009	Wataru Sakai
94	80		(25·10186-43)/9	Oct 14, 2008	Robert Backstrom
95	80		2·10190-1	May 24, 2009	Jo Yeong Uk
96	80		(22·10203+41)/9	Sep 10, 2008	Serge Batalov
97	80		(4·10199-7)/3	Aug 9, 2009	Wataru Sakai
98	79		(65·10184+61)/9	Nov 10, 2009	Dmitry Domanov
99	79		(8·10164-71)/9	Aug 12, 2007	Robert Backstrom
100	79		5·10164+9	Dec 18, 2007	Jo Yeong Uk

4. Large factors found by ECM

Large factors which have 45 digits at least and were found by ECM.

	digits	prime factor	from	B1	sigma	when	who
1	58		(8·10141-17)/9	3897500	2735675386	Oct 31, 2003	Robert Backstrom
2	56		3·10166-1	44000000	3068145495	Sep 14, 2005	Wataru Sakai
3	52		(10178+53)/9	11000000	1762451977	Jul 18, 2008	suberi
4	52		(58·10170+41)/9	3000000	1249571775	Aug 10, 2009	Wataru Sakai
5	51		(29·10170+43)/9	11000000	3500915563	Sep 19, 2009	Jo Yeong Uk
6	51		(32·10205+13)/9	110000000	3446144840	Jun 15, 2009	Wataru Sakai
7	51		(4·10163+17)/3	11000000	861666340	Aug 21, 2008	nuggetprime
8	50		(43·10190+11)/9	11000000	1301257518	Feb 24, 2009	Wataru Sakai
9	50		(16·10244-7)/9	11000000	1786901496	Aug 25, 2009	Dmitry Domanov
10	49		(49·10164+41)/9	3316000	27217913	Mar 28, 2009	Robert Backstrom
11	49		(7·10188-43)/9	43000000	3499185670	May 22, 2009	Dmitry Domanov
12	49		(13·10169+17)/3	20000000	2331681453	Mar 6, 2009	Robert Backstrom
13	49		(4·10229-1)/3	11000000	2062470196	Sep 6, 2008	Serge Batalov
14	49		(5·10176+1)/3	43000000	3476594416	Mar 14, 2009	Wataru Sakai
15	49		(41·10150-23)/9	3000000	4014584566	Jan 29, 2009	Serge Batalov
16	49		(2·10175+1)/3	3000000	1712934266	Oct 4, 2008	Jo Yeong Uk
17	48		(86·10192+31)/9	44000000	896044946	Aug 4, 2006	JMB
18	48		(16·10201-7)/9	43000000	315076985	Sep 16, 2009	Dmitry Domanov
19	48		(67·10172+23)/9	7600000	3670869563	Oct 19, 2008	Robert Backstrom
20	48		10192+9	11000000	413694509	Oct 7, 2007	Jo Yeong Uk
21	48		(73·10192-1)/9	43000000	1770093265	May 22, 2009	Dmitry Domanov
22	48		(59·10158-41)/9	2958000	962280220	Aug 29, 2009	Robert Backstrom
23	48		(2·10171-17)/3	3000000	1868644906	Jul 5, 2009	Wataru Sakai
24	47		9·10195-7	11000000	1202030130	Aug 17, 2009	Wataru Sakai
25	47		(64·10215+53)/9	11000000	1048397889	Jul 7, 2008	Serge Batalov
26	47		(52·10169-61)/9	3000000	616297871	Jun 15, 2009	Wataru Sakai
27	47		(22·10155+41)/9	3870000	219387156	Jul 22, 2008	Robert Backstrom
28	47		(25·10171-61)/9	3000000	3132305148	Sep 4, 2008	Serge Batalov
29	47		10196+9	11000000	2570867251	Nov 11, 2006	Wataru Sakai
30	47		8·10206-1	3000000	1065804300	Aug 1, 2008	Sinkiti Sibata
31	47		(32·10169+31)/9	3000000	1504946988	May 28, 2009	Wataru Sakai
32	47		(10199+17)/9	11000000	1005177743	Feb 14, 2009	Serge Batalov
33	47		(43·10245-7)/9	3000000	45451499	Jan 28, 2009	Serge Batalov
34	47		(25·10165-7)/9	3000000	1593296484	Jul 25, 2007	JMB
35	47		(64·10234+53)/9	10757000	1312137675	Dec 3, 2007	Robert Backstrom
36	47		(22·10179-13)/9	3000000	1048915276	Aug 18, 2008	Sinkiti Sibata
37	47		(55·10165-1)/9	3000000	1761471762	Mar 7, 2008	Jo Yeong Uk
38	47		(64·10297-1)/9	43000000	3599812418	Feb 9, 2009	Serge Batalov
39	47		(43·10190+11)/9	43000000	1827407922	Feb 24, 2009	Wataru Sakai
40	47		(64·10227-1)/9	11000000	2234649575	Jan 21, 2009	Jo Yeong Uk
41	46		(53·10183+1)/9	1000000	761703653	Apr 23, 2009	Makoto Kamada
42	46		(68·10169+13)/9	3744000	1706818246	Jul 27, 2008	Robert Backstrom
43	46		(4·10239-1)/3	11000000	4266053392	Jul 8, 2009	Dmitry Domanov
44	46		(28·10167+71)/9	3000000	3590283382	Nov 13, 2008	Jo Yeong Uk
45	46		4·10222+1	11000000	2238052366	Nov 7, 2008	Serge Batalov
46	46		8·10190-9	3000000	3143978648	Apr 21, 2009	Wataru Sakai
47	46		(10203-7)/3	43000000	4169885631	May 25, 2009	Wataru Sakai
48	46		4·10194+1	11000000	632711195	Jul 27, 2007	Wataru Sakai
49	46		(49·10168-31)/9	3000000	408812994	May 29, 2009	Wataru Sakai
50	46		(58·10150+23)/9	1000000	4284733017	Jul 14, 2009	Jo Yeong Uk
51	46		(26·10162-11)/3	11000000	2633918174	Oct 24, 2009	Dmitry Domanov
52	46		(28·10170-1)/9	11000000	5560633114	Sep 15, 2009	Jo Yeong Uk
53	46		(16·10199-7)/9	11000000	540716867	Jun 3, 2009	Dmitry Domanov
54	46		(64·10333-1)/9	3000000	3772275269	May 26, 2009	Jo Yeong Uk
55	46		(44·10132-53)/9	20000000	2504866877	Mar 8, 2009	Robert Backstrom
56	45		(8·10186-71)/9	6016000	513170549	Oct 18, 2008	Robert Backstrom
57	45		(32·10165-41)/9	2114000	2117395774	Nov 25, 2008	Robert Backstrom
58	45		(35·10157-17)/9	3000000	2131351972	Dec 7, 2008	Serge Batalov
59	45		8·10167+3	1000000	127447873	Jul 18, 2008	Jo Yeong Uk
60	45		(55·10164+17)/9	4640000	1859142445	May 2, 2009	Robert Backstrom
61	45		(4·10189-1)/3	3000000	4103031508	Mar 27, 2007	suberi
62	45		(26·10133-11)/3	1000000	3051414086	Oct 24, 2009	Jo Yeong Uk
63	45		5·10188+3	3000000	2524047625	Jul 4, 2008	suberi
64	45		(14·10197-11)/3	3000000	4276860758	Feb 9, 2009	Serge Batalov
65	45		(64·10202+53)/9	11000000	49343718	Jun 13, 2005	Wataru Sakai
66	45		(2·10171+61)/9	3000000	1058474660	Feb 22, 2009	Serge Batalov
67	45		(13·10177+41)/9	7318000	2046770327	Apr 2, 2008	Robert Backstrom
68	45		(22·10164+17)/3	3000000	798243210	Nov 3, 2009	Wataru Sakai
69	45		2·10195+9	3000000	4163169800	Jul 12, 2009	Dmitry Domanov
70	45		(46·10153+17)/9	3000000	1271141060	Mar 9, 2009	Robert Backstrom
71	45		(38·10153+7)/9	3000000	1546770427	Dec 18, 2008	Serge Batalov
72	45		(86·10148+31)/9	2728500	679331778	Sep 22, 2003	Robert Backstrom
73	45		2·10191+9	3000000	3278687019	Nov 16, 2007	Jo Yeong Uk
74	45		(55·10170+53)/9	11000000	8183252458	Sep 24, 2009	Jo Yeong Uk
75	45		(29·10167+61)/9	3000000	1566598641	Nov 18, 2008	Serge Batalov
76	45		(64·10215+53)/9	43000000	1801021090	Jul 7, 2008	Serge Batalov
77	45		(52·10175-7)/9	11000000	4191283557	Oct 11, 2008	Serge Batalov

5. Nice split

Large factor and cofactor which have 50 digits at least with the same length.

	digits	prime factor	prime cofactor	from	when	who
1	97			6·10198+1	Mar 14, 2009	matsui
2	90			(31·10183-13)/9	Jul 27, 2009	Robert Backstrom
3	84			(8·10196+1)/9	Apr 27, 2009	Jo Yeong Uk
4	83			(62·10170-71)/9	Nov 15, 2009	Dmitry Domanov
5	78			(44·10173-71)/9	Mar 5, 2009	Serge Batalov
6	76			(79·10169-7)/9	Oct 1, 2008	Robert Backstrom
7	69			(22·10139-1)/3	May 5, 2005	Greg Childers
8	69			(28·10146-1)/9	Apr 19, 2005	Sinkiti Sibata
9	68			(34·10137+11)/9	Dec 3, 2008	Serge Batalov
10	68			(22·10197+23)/9	Oct 1, 2009	Wataru Sakai
11	68			(59·10135+31)/9	Oct 19, 2009	Dmitry Domanov
12	68			(59·10141-23)/9	Sep 7, 2009	Robert Backstrom
13	67			(19·10163+71)/9	Jul 13, 2008	Robert Backstrom
14	66			(5·10159-41)/9	Oct 8, 2007	Jo Yeong Uk
15	65			(22·10163-13)/9	Jul 10, 2008	Robert Backstrom
16	65			(16·10145-43)/9	Apr 19, 2008	Robert Backstrom
17	64			(13·10193+23)/9	Oct 1, 2008	Robert Backstrom
18	62			(23·10184+13)/9	Sep 10, 2008	Sinkiti Sibata
19	62			(14·10145+13)/9	Mar 29, 2008	Jo Yeong Uk
20	62			5·10126+9	Dec 16, 2007	Jo Yeong Uk
21	62			(22·10125-1)/3	Oct 24, 2004	Sander Hoogendoorn
22	61			(8·10178-53)/9	Aug 12, 2008	Serge Batalov
23	61			(22·10144-7)/3	Oct 29, 2009	Erik Branger
24	61			(4·10148+41)/9	Jan 31, 2005	Samuel Chong
25	61			(46·10174-1)/9	Aug 8, 2008	Serge Batalov
26	61			(8·10120+7)/3	Oct 20, 2007	Jo Yeong Uk
27	60			5·10118-9	Dec 4, 2007	Jo Yeong Uk
28	59			(43·10160-7)/9	Aug 1, 2007	Sinkiti Sibata
29	58			(67·10143+23)/9	Nov 17, 2004	Greg Childers
30	57			(7·10142+11)/9	Apr 28, 2005	Makoto Kamada
31	57			(22·10136+23)/9	Jul 10, 2008	Serge Batalov
32	57			(53·10149-71)/9	Apr 19, 2009	Robert Backstrom
33	56			4·10154+9	Dec 10, 2007	Robert Backstrom
34	56			(5·10113+7)/3	Sep 26, 2007	Jo Yeong Uk
35	55			(4·10143+41)/9	Jan 21, 2005	Samuel Chong
36	55			(41·10109+31)/9	Feb 3, 2009	Erik Branger
37	55			(5·10134-11)/3	Apr 12, 2008	Sinkiti Sibata
38	55			(25·10223-1)/3	Nov 7, 2008	Serge Batalov
39	54			3·10196-1	Oct 3, 2008	Jo Yeong Uk
40	53			(22·10143-31)/9	Jun 27, 2008	Sinkiti Sibata
41	53			(58·10139-13)/9	Jun 29, 2009	Sinkiti Sibata
42	53			(4·10110-31)/9	May 22, 2004	Naoki Yamamoto
43	52			8·10107+3	Aug 9, 2007	Robert Backstrom
44	52			(16·10144-43)/9	Apr 17, 2008	Robert Backstrom
45	52			(19·10163+53)/9	Jun 3, 2008	Jo Yeong Uk
46	52			(22·10167-7)/3	Nov 9, 2009	Jo Yeong Uk
47	52			(88·10152-7)/9	Jun 22, 2006	Sinkiti Sibata
48	51			(10222+17)/9	Jul 9, 2009	Dmitry Domanov
49	51			(64·10122+53)/9	Jul 2, 2003	Robert Backstrom
50	51			(32·10111-41)/9	Nov 22, 2008	Sinkiti Sibata
51	50			(59·10160-23)/9	Sep 6, 2009	Jo Yeong Uk
52	50			(31·10147+41)/9	Nov 25, 2008	Sinkiti Sibata

6. Unprovable near-repdigit PRPs

Unprovable near-repdigit PRPs which have 20000 digits at least.

	digits	PRP	when searched	who searched
1	103704	(4·10103703-1)/3	Aug 2, 2009	Serge Batalov
2	84239	(2·1084239+1)/3	Jul 6, 2009	Serge Batalov
3	83462	(64·1083461-1)/9	Apr 10, 2009	Serge Batalov
4	56545	(19·1056544-1)/9	Mar 13, 2009	Serge Batalov
5	56454	(55·1056453-1)/9	Mar 12, 2009	Serge Batalov
6	55544	(2·1055544+1)/3	Jun 17, 2009	Serge Batalov
7	53718	(1053718-7)/3	Oct 17, 2004	Makoto Kamada
8	53411	(8·1053411+1)/9	Dec 18, 2008	Serge Batalov
9	53050	(19·1053049-1)/9	Mar 9, 2009	Serge Batalov
10	52764	(61·1052763-7)/9	Feb 27, 2009	Serge Batalov
11	43754	(25·1043753-1)/3	Jan 18, 2009	Serge Batalov
12	43272	(61·1043271-7)/9	Jan 2008	Maksym Voznyy
13	40890	(16·1040889-1)/3	Jan 24, 2009	Serge Batalov
14	39606	(2·1039606+1)/3	Jun 20, 2009	Serge Batalov
15	39464	(5·1039464+31)/9	Jan 6, 2009	Serge Batalov
16	38690	(5·1038690+31)/9	Jan 6, 2009	Serge Batalov
17	37597	1037597-9	Jan 2008	Jason Earls
18	35925	1035925-9	Jan 2008	Jason Earls
19	35754	(16·1035753-1)/3	Jan 23, 2009	Serge Batalov
20	31632	(61·1031631-7)/9	Jan 2008	Maksym Voznyy
21	30977	(61·1030976-7)/9	Jan 2008	Maksym Voznyy
22	30178	(1030178-7)/3	Mar 20, 2004	Makoto Kamada
23	26045	1026045-3	Nov 2002	Henri Lifchitz
24	25324	(1025324-7)/3	Feb 7, 2004	Makoto Kamada
25	24549	(1024549-7)/3	Feb 7, 2004	Makoto Kamada
26	24253	(1024253-7)/3	Feb 7, 2004	Makoto Kamada
27	23365	(1023365-7)/3	Feb 7, 2004	Makoto Kamada
28	22973	(1022973+53)/9	Oct 2008	Lelio R Paula
29	22718	(1022718-7)/3	Feb 6, 2004	Makoto Kamada
30	22094	(61·1022093-7)/9	Jan 6, 2008	Maksym Voznyy
31	21873	1021873-3	Nov 2002	Henri Lifchitz
32	20016	(1020016+17)/9	Oct 2008	Lelio R Paula

7. Unprovable quasi-repdigit PRPs

Unprovable quasi-repdigit PRPs except Plateau and Depression PRPs, which have 20000 digits at least.

	digits	PRP	when searched	who searched
1	96744	(28·1096743+71)/9	Dec 8, 2008	Serge Batalov
2	91216	7·1091215+3	Nov 7, 2009	Erik Branger
3	59136	(28·1059135+53)/9	Nov 19, 2008	Serge Batalov
4	56899	(35·1056898-17)/9	Feb 28, 2009	Serge Batalov
5	56780	7·1056779+3	Nov 7, 2009	Erik Branger
6	50712	1050711+7	Dec 2007	Jason Earls
7	48110	1048109+9	Dec 2007	Jason Earls
8	43187	1043186+9	Dec 2007	Jason Earls
9	40744	(76·1040743-31)/9	Feb 27, 2009	Serge Batalov
10	39856	(38·1039855+61)/9	Oct 15, 2008	Serge Batalov
11	38080	7·1038079+3	Nov 7, 2009	Erik Branger
12	35991	(31·1035990+23)/9	Feb 23, 2009	Serge Batalov
13	35428	(76·1035427-31)/9	Feb 25, 2009	Serge Batalov
14	32797	7·1032796+3	Nov 7, 2009	Erik Branger
15	31811	1031810+9	Oct 14, 2006	Dirk Augustin
16	30222	1030221+7	Nov 2007	Jason Earls
17	28339	7·1028338+3	Nov 7, 2009	Erik Branger
18	27223	(19·1027222+53)/9	Oct 15, 2008	Serge Batalov
19	26928	1026927+3	Dec 2007	Jason Earls
20	26264	(58·1026263-31)/9	Nov 2, 2008	Serge Batalov
21	26195	(67·1026194-13)/9	Oct 15, 2008	Serge Batalov
22	23637	1023636+7	Nov 2007	Jason Earls
23	22049	(13·1022048-7)/3	Feb 23, 2009	Serge Batalov
24	21718	1021717+7	Feb 2004	Thomas Masser
25	20892	7·1020891+9	Jan 12, 2008	Sinkiti Sibata
26	20865	(64·1020864+17)/9	Oct 14, 2008	Serge Batalov
27	20764	(28·1020763+71)/9	Nov 17, 2008	Serge Batalov

See also Plateau and Depression Primes maintained by Patrick De Geest.

8. Quasi-repdigit twin primes

Quasi-repdigit twin primes which have 100 digits at least.

	digits	p, p+2	when searched	who searched	when certified	who certified
1	3884	(13·103883+23)/9 (13·103883+41)/9	Dec 17, 2004	Makoto Kamada	May 27, 2006	Tyler Cadigan
2	413	(4·10412+11)/3 (4·10412+17)/3	Sep 20, 2004	Makoto Kamada	Dec 7, 2004	Julien Peter Benney