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Table of contents

1. Top 100 large numbers factored by SNFS
2. 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	222		P55 · P55 · P114	(25·10223-1)/3	Nov 7, 2008	Serge Batalov
2	222		P51 · P51 · P120	(10222+17)/9	Jul 9, 2009	Dmitry Domanov
3	218		P54 · P165	4·10217-9	Jun 27, 2009	Robert Backstrom
4	216		P77 · P139	4·10219-9	May 1, 2009	Robert Backstrom
5	212		P87 · P125	2·10216-1	Jul 5, 2009	Robert Backstrom
6	211		P57 · P154	4·10217+1	Apr 17, 2009	Robert Backstrom
7	211		P57 · P154	(64·10321-1)/9	Apr 8, 2009	Robert Backstrom
8	208		P100 · P108	4·10209+1	Feb 17, 2009	Serge Batalov
9	207		P60 · P148	(10211+53)/9	Mar 20, 2009	Serge Batalov
10	206		P50 · P157	(19·10205-7)/3	Jun 9, 2009	Wataru Sakai
11	206		P67 · P139	(16·10205-1)/3	Nov 10, 2008	Robert Backstrom
12	206		P103 · P104	(14·10205-11)/3	Feb 22, 2009	Wataru Sakai
13	206		P53 · P75 · P79	(37·10205+17)/9	Feb 26, 2009	Robert Backstrom
14	206		P68 · P139	(25·10205-43)/9	Nov 20, 2008	Robert Backstrom
15	206		P58 · P148	(7·10207-43)/9	Jun 16, 2009	Robert Backstrom
16	205		P100 · P106	(4·10207-1)/3	Jul 19, 2008	Serge Batalov
17	205		P51 · P73 · P82	(64·10211-1)/9	Jun 10, 2009	Robert Backstrom
18	205		P48 · P71 · P88	(11·10204-17)/3	Dec 16, 2008	Robert Backstrom
19	205		P102 · P103	(37·10204+17)/9	Feb 5, 2009	Robert Backstrom
20	204		P52 · P153	(52·10204+11)/9	Jun 17, 2009	Markus Tervooren
21	204		P56 · P149	(47·10204+7)/9	Mar 24, 2009	Robert Backstrom
22	204		P79 · P126	(13·10203+17)/3	Feb 8, 2009	Wataru Sakai
23	204		P66 · P138	(64·10203-1)/9	Nov 4, 2008	Robert Backstrom
24	204		P40 · P164	(38·10203+61)/9	Jan 26, 2009	Wataru Sakai
25	203		P54 · P67 · P83	(10207+17)/9	Mar 30, 2009	Robert Backstrom
26	203		P42 · P59 · P102	(53·10203-17)/9	Jun 2, 2009	Robert Backstrom
27	203		P93 · P110	(41·10203+31)/9	Feb 20, 2009	Robert Backstrom
28	202		P80 · P123	(22·10203+41)/9	Sep 10, 2008	Serge Batalov
29	202		P60 · P143	(56·10202+43)/9	Jun 28, 2009	Dmitry Domanov
30	202		P58 · P144	(44·10202-17)/9	Mar 10, 2009	Robert Backstrom
31	202		P86 · P117	(41·10203-23)/9	Mar 16, 2009	Robert Backstrom
32	202		P47 · P55 · P100	(35·10202-17)/9	Mar 5, 2009	Robert Backstrom
33	201		P77 · P125	(79·10200-7)/9	Dec 25, 2006	Alexander Mkrtychyan
34	201		P53 · P70 · P79	(22·10200-31)/9	Aug 1, 2008	Serge Batalov
35	201		P37 · P41 · P123	(52·10200+11)/9	May 28, 2009	Wataru Sakai
36	200		P73 · P128	4·10203+1	May 8, 2009	Wataru Sakai
37	200		P47 · P62 · P92	(32·10204-41)/9	Dec 7, 2008	Robert Backstrom
38	200		P41 · P76 · P84	(46·10202+17)/9	Jun 11, 2009	matsui
39	200		P84 · P116	6·10200+1	Jul 4, 2008	Serge Batalov
40	200		P52 · P65 · P84	(14·10200-23)/9	Oct 30, 2008	Robert Backstrom
41	200		P60 · P67 · P73	(56·10200+61)/9	May 28, 2009	Robert Backstrom
42	199		P54 · P73 · P74	(7·10199-61)/9	Nov 23, 2008	Wataru Sakai
43	199		P61 · P138	(2·10199-17)/3	Aug 31, 2008	Wataru Sakai
44	199		P52 · P148	(53·10198-17)/9	May 16, 2009	Jo Yeong Uk
45	199		P34 · P80 · P86	(29·10198+61)/9	Nov 30, 2008	Wataru Sakai
46	199		P82 · P118	3·10198+1	Sep 8, 2008	Serge Batalov
47	199		P48 · P69 · P83	(23·10198-41)/9	Nov 14, 2008	Wataru Sakai
48	199		P46 · P154	(7·10200+11)/9	Apr 25, 2009	Wataru Sakai
49	199		P90 · P110	(5·10198-17)/3	Dec 1, 2008	Jo Yeong Uk
50	199		P60 · P66 · P74	(8·10199-17)/9	Dec 15, 2008	Wataru Sakai
51	199		P55 · P144	4·10200-3	Dec 6, 2008	Wataru Sakai
52	198		P40 · P158	(28·10198+53)/9	Dec 28, 2008	Wataru Sakai
53	198		P87 · P112	4·10198+9	Feb 18, 2009	matsui
54	197		P54 · P144	(8·10197+1)/9	Nov 4, 2008	Wataru Sakai
55	197		P96 · P102	(2·10197+1)/3	Nov 1, 2008	Wataru Sakai
56	197		P67 · P131	6·10196+1	Jul 21, 2008	Wataru Sakai
57	197		P52 · P146	(16·10197-7)/9	May 26, 2009	Dmitry Domanov
58	197		P76 · P122	(47·10196+61)/9	Apr 17, 2009	Jo Yeong Uk
59	197		P52 · P60 · P87	2·10200-3	Feb 14, 2009	matsui
60	197		P57 · P66 · P74	(37·10196+53)/9	Dec 28, 2008	Wataru Sakai
61	197		P54 · P54 · P90	3·10196-1	Oct 3, 2008	Jo Yeong Uk
62	197		P78 · P119	(5·10197-11)/3	May 22, 2009	Robert Backstrom
63	197		P49 · P148	(32·10196+31)/9	Feb 12, 2009	Robert Backstrom
64	197		P73 · P124	(31·10196-13)/9	Feb 9, 2009	Robert Backstrom
65	196		P60 · P136	4·10198+1	Mar 3, 2009	Wataru Sakai
66	196		P44 · P49 · P104	(13·10195+17)/3	Feb 13, 2009	Jo Yeong Uk
67	196		P63 · P134	(38·10195+61)/9	Jan 6, 2009	Wataru Sakai
68	196		P73 · P124	(37·10195+53)/9	Apr 4, 2009	Jo Yeong Uk
69	196		P88 · P108	(19·10196+71)/9	Jan 19, 2009	Wataru Sakai
70	196		P55 · P141	(64·10197-1)/9	Oct 23, 2008	Robert Backstrom
71	196		P87 · P109	(82·10198-1)/9	May 19, 2009	Robert Backstrom
72	196		P48 · P149	(22·10195+41)/9	Sep 21, 2008	Robert Backstrom
73	196		P56 · P140	(5·10195+7)/3	May 17, 2008	Sinkiti Sibata
74	196		P64 · P132	10196+3	Dec 9, 2008	Wataru Sakai
75	196		P91 · P105	(22·10198-1)/3	May 15, 2009	Robert Backstrom
76	196		P51 · P145	(38·10196-11)/9	May 13, 2009	Robert Backstrom
77	195		P44 · P53 · P99	(82·10195+71)/9	Apr 14, 2009	Wataru Sakai
78	195		P75 · P121	(73·10194-1)/9	Sep 29, 2008	Wataru Sakai
79	195		P55 · P141	(13·10195-1)/3	Apr 21, 2009	Sinkiti Sibata
80	195		P44 · P151	(47·10195+7)/9	May 5, 2009	Robert Backstrom
81	195		P88 · P108	5·10194+9	Sep 6, 2008	Jo Yeong Uk
82	195		P76 · P120	5·10194-1	Sep 20, 2007	Sinkiti Sibata
83	195		P49 · P147	(34·10194+11)/9	Dec 15, 2008	Wataru Sakai
84	195		P96 · P100	(25·10195-61)/9	Oct 8, 2008	Tyler Cadigan
85	195		P55 · P140	8·10196+3	May 6, 2009	Robert Backstrom
86	195		P74 · P121	(26·10195-17)/9	May 2, 2009	Robert Backstrom
87	195		P71 · P124	2·10197-3	May 14, 2009	Wataru Sakai
88	194		P40 · P155	5·10195-7	Feb 28, 2009	Wataru Sakai
89	194		P73 · P122	9·10198+1	May 23, 2009	Wataru Sakai
90	194		P90 · P105	(38·10193+43)/9	Jan 8, 2009	Jo Yeong Uk
91	194		P49 · P145	(13·10193+41)/9	Sep 12, 2008	Robert Backstrom
92	194		P97 · P97	6·10198+1	Mar 14, 2009	matsui
93	193		P57 · P136	(4·10193-31)/9	Aug 12, 2008	Jo Yeong Uk
94	193		P54 · P140	8·10197-3	Jun 9, 2009	Wataru Sakai
95	193		P92 · P102	(68·10192+13)/9	Sep 1, 2008	Robert Backstrom
96	193		P43 · P66 · P85	9·10193-1	Sep 17, 2008	Robert Backstrom
97	193		P36 · P60 · P98	5·10194-9	Oct 18, 2008	Wataru Sakai
98	193		P52 · P141	10360+1	Jul 4, 2005	Tomoya Adachi
99	192		P65 · P128	(34·10193+11)/9	Feb 10, 2009	Wataru Sakai
100	192		P64 · P64 · P66	(13·10193+23)/9	Oct 1, 2008	Robert Backstrom

2. Large numbers factored by GNFS

Large numbers which have 120 digits at least and were factored by GNFS.

	digits	composite number	prime factors	from	when	who
1	148		P63 · P85	(16·10220-61)/9	Dec 24, 2008	Serge Batalov
2	145		P52 · P93	4·10212+9	May 12, 2009	Markus Tervooren
3	144		P70 · P74	(64·10232+53)/9	Aug 13, 2008	Serge Batalov
4	140		P53 · P88	(16·10214-61)/9	Aug 4, 2008	Serge Batalov
5	140		P49 · P92	(26·10203+1)/9	Jun 11, 2009	Dmitry Domanov
6	140		P45 · P95	4·10200+7	Mar 6, 2008	Tyler Cadigan
7	139		P60 · P79	6·10199+1	Jul 10, 2008	Tyler Cadigan
8	138		P60 · P79	(10196+53)/9	Feb 25, 2009	Tyler Cadigan
9	138		P49 · P89	(10198+53)/9	Aug 1, 2008	Tyler Cadigan
10	138		P64 · P74	(7·10196-43)/9	May 9, 2008	Wataru Sakai
11	137		P49 · P88	(55·10199+53)/9	Jun 5, 2009	Sinkiti Sibata
12	137		P47 · P91	2·10207-1	Jun 17, 2009	Andreas Tete
13	136		P59 · P78	9·10249-1	May 29, 2009	matsui
14	135		P49 · P86	(4·10195-1)/3	Nov 17, 2007	Jo Yeong Uk
15	134		P47 · P88	8·10190-1	May 28, 2008	Jo Yeong Uk
16	134		P50 · P84	8·10193-9	May 23, 2009	Sinkiti Sibata
17	133		P43 · P91	(2·10200+61)/9	May 15, 2009	Sinkiti Sibata
18	133		P45 · P88	(25·10190-7)/9	Mar 26, 2009	Andreas Tete
19	132		P51 · P81	6·10194+1	Apr 27, 2009	Tyler Cadigan
20	131		P60 · P72	(22·10186-31)/9	Jul 29, 2008	Sinkiti Sibata
21	131		P44 · P87	(52·10188+11)/9	Apr 21, 2009	Andreas Tete
22	130		P46 · P84	(4·10203-1)/3	May 5, 2009	Sinkiti Sibata
23	130		P60 · P70	(85·10186+41)/9	Feb 15, 2009	Erik Branger
24	129		P61 · P69	3·10191+1	Jul 3, 2008	matsui
25	128		P46 · P83	4·10187-9	Nov 11, 2008	Sinkiti Sibata
26	128		P63 · P66	2·10191+3	May 7, 2009	Ignacio Santos
27	127		P39 · P89	8·10187-1	Apr 24, 2008	Jo Yeong Uk
28	127		P43 · P84	(73·10191-1)/9	May 6, 2009	Ignacio Santos
29	126		P60 · P67	(64·10309-1)/9	Feb 16, 2009	Wataru Sakai
30	126		P44 · P82	(4·10241-1)/3	Mar 25, 2009	Ignacio Santos
31	126		P50 · P76	(16·10182-7)/9	Apr 22, 2008	Wataru Sakai
32	126		P55 · P71	(5·10185-23)/9	Aug 10, 2008	Serge Batalov
33	125		P57 · P68	(49·10181+23)/9	May 4, 2009	Ignacio Santos
34	125		P56 · P70	4·10199+9	Feb 20, 2009	Erik Branger
35	125		P58 · P68	(31·10168+41)/9	Mar 9, 2009	Andreas Tete
36	125		P49 · P76	(16·10189-7)/9	May 26, 2009	Dmitry Domanov
37	125		P46 · P79	(10181+17)/9	Sep 30, 2008	Justin Card
38	124		P57 · P68	2·10177-3	May 17, 2009	Dmitry Domanov
39	124		P43 · P82	(35·10181-53)/9	Nov 19, 2008	Erik Branger
40	124		P59 · P65	(5·10198-11)/3	Aug 4, 2008	Tyler Cadigan
41	124		P62 · P63	8·10197+9	Jun 1, 2008	Tyler Cadigan
42	124		P59 · P65	(5·10190+13)/9	May 30, 2008	Tyler Cadigan
43	124		P61 · P63	(35·10176-71)/9	Apr 23, 2009	Ignacio Santos
44	123		P59 · P65	3·10179-1	Feb 16, 2008	matsui
45	123		P53 · P71	6·10192+7	May 28, 2008	Tyler Cadigan
46	123		P51 · P72	(17·10179-11)/3	May 21, 2009	Sinkiti Sibata
47	123		P48 · P75	(29·10199-11)/9	Apr 1, 2009	Andreas Tete
48	123		P49 · P75	(53·10179-17)/9	May 18, 2009	Erik Branger
49	123		P59 · P64	(16·10190-61)/9	Feb 12, 2008	Tyler Cadigan
50	123		P58 · P65	(25·10157+11)/9	Sep 22, 2008	Sinkiti Sibata
51	123		P50 · P73	(37·10194+71)/9	Apr 28, 2009	Ignacio Santos
52	122		P40 · P83	(8·10173-11)/3	Apr 22, 2009	Ignacio Santos
53	122		P41 · P82	(44·10200-53)/9	Apr 25, 2009	Sinkiti Sibata
54	122		P51 · P72	7·10187-9	May 12, 2009	Dmitry Domanov
55	122		P41 · P82	(26·10176-71)/9	Oct 1, 2008	Sinkiti Sibata
56	122		P39 · P41 · P43	(2·10188-17)/3	May 31, 2007	Sinkiti Sibata
57	122		P40 · P82	(49·10173-31)/9	Apr 21, 2009	Ignacio Santos
58	122		P39 · P84	(25·10173+11)/9	Apr 21, 2009	Ignacio Santos
59	122		P51 · P71	(52·10183+11)/9	Apr 20, 2009	Ignacio Santos
60	122		P54 · P68	(37·10186+17)/9	Apr 19, 2009	Ignacio Santos
61	122		P44 · P79	(32·10194+13)/9	Apr 18, 2009	Ignacio Santos
62	122		P55 · P67	(85·10185+41)/9	Aug 12, 2008	Serge Batalov
63	122		P45 · P77	(19·10176+53)/9	Aug 13, 2008	Serge Batalov
64	122		P46 · P76	(2·10178+61)/9	Mar 12, 2008	Robert Backstrom
65	122		P61 · P61	(8·10178-53)/9	Aug 12, 2008	Serge Batalov
66	122		P51 · P71	5·10180-7	Jul 11, 2008	Sinkiti Sibata
67	122		P44 · P78	(28·10176+71)/9	Apr 17, 2009	Ignacio Santos
68	121		P33 · P45 · P45	(47·10187+61)/9	Apr 16, 2009	Ignacio Santos
69	121		P57 · P64	(37·10178+17)/9	Apr 16, 2009	Ignacio Santos
70	121		P54 · P68	5·10188+9	Apr 22, 2009	Sinkiti Sibata
71	121		P59 · P63	(43·10180+11)/9	Apr 15, 2009	Jeff Gilchrist
72	121		P56 · P66	(16·10199-43)/9	Aug 4, 2008	Serge Batalov
73	121		P44 · P78	(47·10182+61)/9	Apr 15, 2009	Jeff Gilchrist
74	121		P44 · P78	(43·10177-61)/9	Apr 14, 2009	Jeff Gilchrist
75	121		P38 · P84	8·10185+9	Nov 28, 2008	Serge Batalov
76	121		P50 · P71	(35·10190+1)/9	Feb 1, 2009	Ignacio Santos
77	121		P40 · P81	(55·10200+17)/9	May 3, 2009	Sinkiti Sibata
78	121		P59 · P62	5·10179-7	Sep 28, 2007	Sinkiti Sibata
79	120		P44 · P77	(71·10182-17)/9	Jan 4, 2007	Alexander Mkrtychyan
80	120		P54 · P67	(2·10197+7)/9	Dec 4, 2006	Tyler Cadigan
81	120		P48 · P73	(4·10179-1)/3	Nov 15, 2006	Tyler Cadigan
82	120		P51 · P70	(14·10170-23)/9	Dec 4, 2008	Jo Yeong Uk
83	120		P38 · P83	10187+9	Oct 7, 2006	Tyler Cadigan
84	120		P58 · P63	(22·10189-1)/3	Dec 13, 2006	Tyler Cadigan
85	120		P29 · P43 · P49	10177+9	Aug 11, 2007	Sinkiti Sibata
86	120		P43 · P78	(86·10171+31)/9	Jan 10, 2008	Jo Yeong Uk
87	120		P44 · P76	(5·10172+31)/9	Aug 15, 2008	Jo Yeong Uk
88	120		P57 · P64	(8·10189-71)/9	Dec 21, 2006	Tyler Cadigan
89	120		P54 · P66	(25·10192+11)/9	Oct 4, 2008	Jo Yeong Uk
90	120		P59 · P62	(25·10165+11)/9	Sep 23, 2008	Sinkiti Sibata
91	120		P59 · P61	(49·10161-31)/9	Apr 5, 2009	Andreas Tete
92	120		P35 · P85	(28·10165+71)/9	Nov 26, 2008	Jo Yeong Uk
93	120		P57 · P64	(25·10172+11)/9	Oct 1, 2008	Jo Yeong Uk
94	120		P51 · P69	(56·10186+61)/9	May 29, 2009	Jo Yeong Uk
95	120		P54 · P66	(49·10199-13)/9	Mar 24, 2009	Ignacio Santos
96	120		P51 · P69	(47·10170+43)/9	Mar 24, 2009	Robert Backstrom
97	120		P59 · P61	9·10184+1	May 23, 2007	Sinkiti Sibata
98	120		P38 · P82	(61·10169-7)/9	Oct 6, 2007	Bryan Koen

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	100		(4·10207-1)/3	Jul 19, 2008	Serge Batalov
4	100		4·10209+1	Feb 17, 2009	Serge Batalov
5	97		6·10198+1	Mar 14, 2009	matsui
6	96		(2·10197+1)/3	Nov 1, 2008	Wataru Sakai
7	96		(25·10195-61)/9	Oct 8, 2008	Tyler Cadigan
8	94		(17·10192+1)/9	Aug 25, 2008	Robert Backstrom
9	93		(41·10203+31)/9	Feb 20, 2009	Robert Backstrom
10	92		(68·10192+13)/9	Sep 1, 2008	Robert Backstrom
11	91		(22·10198-1)/3	May 15, 2009	Robert Backstrom
12	90		(26·10183-17)/9	Oct 29, 2008	Jo Yeong Uk
13	90		(47·10191+7)/9	Jun 28, 2009	Wataru Sakai
14	90		(38·10193+43)/9	Jan 8, 2009	Jo Yeong Uk
15	90		(5·10198-17)/3	Dec 1, 2008	Jo Yeong Uk
16	89		(4·10190-31)/9	Nov 2, 2007	Jo Yeong Uk
17	89		(4·10192-13)/9	Feb 19, 2008	Jo Yeong Uk
18	89		9·10185+7	Nov 22, 2008	Wataru Sakai
19	89		(4·10188-31)/9	Oct 17, 2007	Jo Yeong Uk
20	88		(82·10185-1)/9	Jun 15, 2008	Robert Backstrom
21	88		(19·10196+71)/9	Jan 19, 2009	Wataru Sakai
22	88		5·10194+9	Sep 6, 2008	Jo Yeong Uk
23	88		(5·10179-17)/3	Jul 9, 2007	Robert Backstrom
24	87		(10183+53)/9	Jan 23, 2009	Tyler Cadigan
25	87		(82·10198-1)/9	May 19, 2009	Robert Backstrom
26	87		2·10216-1	Jul 5, 2009	Robert Backstrom
27	87		4·10198+9	Feb 18, 2009	matsui
28	86		4·10180+3	Jun 17, 2007	Sinkiti Sibata
29	86		(32·10190+31)/9	Jun 16, 2009	Wataru Sakai
30	86		(11·10181+43)/9	Mar 5, 2008	Jo Yeong Uk
31	86		(41·10203-23)/9	Mar 16, 2009	Robert Backstrom
32	85		10183+3	Mar 3, 2008	Robert Backstrom
33	84		6·10192-1	Mar 16, 2009	matsui
34	84		(16·10181-61)/9	Sep 9, 2007	Robert Backstrom
35	84		(25·10181-43)/9	Sep 30, 2008	Robert Backstrom
36	84		(8·10196+1)/9	Apr 27, 2009	Jo Yeong Uk
37	84		6·10200+1	Jul 4, 2008	Serge Batalov
38	84		(52·10175+11)/9	Apr 18, 2009	Ignacio Santos
39	84		4·10183-9	Nov 12, 2008	Serge Batalov
40	84		(56·10190-11)/9	May 24, 2009	Robert Backstrom
41	84		(29·10184+43)/9	Dec 20, 2008	Robert Backstrom
42	83		(52·10180+11)/9	Apr 24, 2009	Ignacio Santos
43	83		(67·10175+23)/9	Oct 9, 2008	Jo Yeong Uk
44	83		(44·10180+1)/9	Mar 12, 2009	Sinkiti Sibata
45	83		(26·10170-53)/9	Oct 8, 2008	Serge Batalov
46	83		(10192+53)/9	May 18, 2008	Wataru Sakai
47	83		(38·10186+61)/9	Jan 12, 2009	Sinkiti Sibata
48	82		(5·10171-23)/9	Oct 16, 2008	Robert Backstrom
49	82		(23·10188+13)/9	Nov 4, 2008	Wataru Sakai
50	82		(16·10177+11)/9	Sep 9, 2008	Robert Backstrom
51	82		(37·10173+17)/9	Dec 21, 2008	Jo Yeong Uk
52	82		3·10198+1	Sep 8, 2008	Serge Batalov
53	82		(17·10185-53)/9	Jun 3, 2008	Robert Backstrom
54	82		(14·10180+1)/3	Mar 28, 2009	Ignacio Santos
55	82		(23·10174+1)/3	Mar 1, 2007	Tyler Cadigan
56	81		(37·10167-1)/9	May 14, 2007	Robert Backstrom
57	81		(2·10185+1)/3	Aug 5, 2008	matsui
58	81		(85·10180+41)/9	Apr 26, 2009	Ignacio Santos
59	81		(52·10181-7)/9	Sep 20, 2007	Robert Backstrom
60	81		(67·10166+23)/9	Jan 12, 2008	Robert Backstrom
61	81		(2·10178+1)/3	Jul 17, 2008	Wataru Sakai
62	81		8·10176+9	Feb 24, 2008	matsui
63	81		(43·10184-7)/9	Jan 6, 2009	Tyler Cadigan
64	80		6·10180+1	Jul 5, 2009	Tyler Cadigan
65	80		(5·10175+1)/3	Jun 15, 2008	Kenji Ibusuki
66	80		(29·10198+61)/9	Nov 30, 2008	Wataru Sakai
67	80		(19·10175+71)/9	Jun 18, 2008	Jo Yeong Uk
68	80		(13·10171-1)/3	Jun 7, 2007	Robert Backstrom
69	80		(25·10186-43)/9	Oct 14, 2008	Robert Backstrom
70	80		2·10190-1	May 24, 2009	Jo Yeong Uk
71	80		(22·10203+41)/9	Sep 10, 2008	Serge Batalov
72	79		(8·10164-71)/9	Aug 12, 2007	Robert Backstrom
73	79		5·10164+9	Dec 18, 2007	Jo Yeong Uk
74	79		(13·10165-7)/3	Dec 25, 2008	Serge Batalov
75	79		5·10181-7	Sep 28, 2008	Robert Backstrom
76	79		(37·10166+17)/9	Dec 11, 2008	Serge Batalov
77	79		(13·10171+23)/9	Mar 12, 2008	Jo Yeong Uk
78	79		(25·10169-43)/9	Sep 15, 2008	Serge Batalov
79	79		(64·10177+53)/9	Sep 9, 2008	Robert Backstrom
80	79		(13·10203+17)/3	Feb 8, 2009	Wataru Sakai
81	79		(5·10165-11)/3	Apr 14, 2008	Robert Backstrom
82	79		8·10170-3	Jun 8, 2008	matsui
83	79		7·10180+9	Feb 8, 2009	Wataru Sakai
84	79		(4·10168+23)/9	Jun 13, 2008	Robert Backstrom
85	79		(4·10164-13)/9	Jun 26, 2007	Robert Backstrom
86	78		5·10183-1	Jun 9, 2009	Wataru Sakai
87	78		(83·10166+61)/9	Jan 17, 2008	Robert Backstrom
88	78		(5·10197-11)/3	May 22, 2009	Robert Backstrom
89	78		(8·10178+7)/3	Nov 12, 2007	Jo Yeong Uk
90	78		(13·10172+41)/9	Jun 27, 2008	Robert Backstrom
91	78		(8·10166-11)/3	Sep 2, 2008	Robert Backstrom
92	78		(28·10179+71)/9	Nov 28, 2008	Robert Backstrom
93	78		(19·10185+11)/3	Jun 28, 2009	Robert Backstrom
94	78		(29·10191-11)/9	Nov 23, 2008	Kenji Ibusuki
95	78		(44·10173-71)/9	Mar 5, 2009	Serge Batalov
96	78		(19·10171+53)/9	Jun 7, 2008	Robert Backstrom
97	78		10181-9	May 12, 2008	Wataru Sakai
98	77		(17·10156-53)/9	May 5, 2008	Robert Backstrom
99	77		(47·10168-11)/9	Mar 25, 2009	Ignacio Santos
100	77		4·10219-9	May 1, 2009	Robert Backstrom

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	51		(32·10205+13)/9	110000000	3446144840	Jun 15, 2009	Wataru Sakai
5	51		(4·10163+17)/3	11000000	861666340	Aug 21, 2008	nuggetprime
6	50		(43·10190+11)/9	11000000	1301257518	Feb 24, 2009	Wataru Sakai
7	49		(49·10164+41)/9	3316000	27217913	Mar 28, 2009	Robert Backstrom
8	49		(7·10188-43)/9	43000000	3499185670	May 22, 2009	Dmitry Domanov
9	49		(13·10169+17)/3	20000000	2331681453	Mar 6, 2009	Robert Backstrom
10	49		(4·10229-1)/3	11000000	2062470196	Sep 6, 2008	Serge Batalov
11	49		(5·10176+1)/3	43000000	3476594416	Mar 14, 2009	Wataru Sakai
12	49		(41·10150-23)/9	3000000	4014584566	Jan 29, 2009	Serge Batalov
13	49		(2·10175+1)/3	3000000	1712934266	Oct 4, 2008	Jo Yeong Uk
14	48		(86·10192+31)/9	44000000	896044946	Aug 4, 2006	JMB
15	48		(67·10172+23)/9	7600000	3670869563	Oct 19, 2008	Robert Backstrom
16	48		10192+9	11000000	413694509	Oct 7, 2007	Jo Yeong Uk
17	48		(73·10192-1)/9	43000000	1770093265	May 22, 2009	Dmitry Domanov
18	48		(2·10171-17)/3	3000000	1868644906	Jul 5, 2009	Wataru Sakai
19	47		(64·10215+53)/9	11000000	1048397889	Jul 7, 2008	Serge Batalov
20	47		(52·10169-61)/9	3000000	616297871	Jun 15, 2009	Wataru Sakai
21	47		(22·10155+41)/9	3870000	219387156	Jul 22, 2008	Robert Backstrom
22	47		(25·10171-61)/9	3000000	3132305148	Sep 4, 2008	Serge Batalov
23	47		10196+9	11000000	2570867251	Nov 11, 2006	Wataru Sakai
24	47		8·10206-1	3000000	1065804300	Aug 1, 2008	Sinkiti Sibata
25	47		(32·10169+31)/9	3000000	1504946988	May 28, 2009	Wataru Sakai
26	47		(10199+17)/9	11000000	1005177743	Feb 14, 2009	Serge Batalov
27	47		(43·10245-7)/9	3000000	45451499	Jan 28, 2009	Serge Batalov
28	47		(25·10165-7)/9	3000000	1593296484	Jul 25, 2007	JMB
29	47		(64·10234+53)/9	10757000	1312137675	Dec 3, 2007	Robert Backstrom
30	47		(22·10179-13)/9	3000000	1048915276	Aug 18, 2008	Sinkiti Sibata
31	47		(55·10165-1)/9	3000000	1761471762	Mar 7, 2008	Jo Yeong Uk
32	47		(64·10297-1)/9	43000000	3599812418	Feb 9, 2009	Serge Batalov
33	47		(43·10190+11)/9	43000000	1827407922	Feb 24, 2009	Wataru Sakai
34	47		(64·10227-1)/9	11000000	2234649575	Jan 21, 2009	Jo Yeong Uk
35	46		(53·10183+1)/9	1000000	761703653	Apr 23, 2009	Makoto Kamada
36	46		(68·10169+13)/9	3744000	1706818246	Jul 27, 2008	Robert Backstrom
37	46		(4·10239-1)/3	11000000	4266053392	Jul 8, 2009	Dmitry Domanov
38	46		(28·10167+71)/9	3000000	3590283382	Nov 13, 2008	Jo Yeong Uk
39	46		4·10222+1	11000000	2238052366	Nov 7, 2008	Serge Batalov
40	46		8·10190-9	3000000	3143978648	Apr 21, 2009	Wataru Sakai
41	46		(10203-7)/3	43000000	4169885631	May 25, 2009	Wataru Sakai
42	46		4·10194+1	11000000	632711195	Jul 27, 2007	Wataru Sakai
43	46		(49·10168-31)/9	3000000	408812994	May 29, 2009	Wataru Sakai
44	46		(16·10199-7)/9	11000000	540716867	Jun 3, 2009	Dmitry Domanov
45	46		(64·10333-1)/9	3000000	3772275269	May 26, 2009	Jo Yeong Uk
46	46		(44·10132-53)/9	20000000	2504866877	Mar 8, 2009	Robert Backstrom
47	45		(8·10186-71)/9	6016000	513170549	Oct 18, 2008	Robert Backstrom
48	45		(32·10165-41)/9	2114000	2117395774	Nov 25, 2008	Robert Backstrom
49	45		(35·10157-17)/9	3000000	2131351972	Dec 7, 2008	Serge Batalov
50	45		8·10167+3	1000000	127447873	Jul 18, 2008	Jo Yeong Uk
51	45		(55·10164+17)/9	4640000	1859142445	May 2, 2009	Robert Backstrom
52	45		(4·10189-1)/3	3000000	4103031508	Mar 27, 2007	suberi
53	45		5·10188+3	3000000	2524047625	Jul 4, 2008	suberi
54	45		(14·10197-11)/3	3000000	4276860758	Feb 9, 2009	Serge Batalov
55	45		(64·10202+53)/9	11000000	49343718	Jun 13, 2005	Wataru Sakai
56	45		(2·10171+61)/9	3000000	1058474660	Feb 22, 2009	Serge Batalov
57	45		(13·10177+41)/9	7318000	2046770327	Apr 2, 2008	Robert Backstrom
58	45		(46·10153+17)/9	3000000	1271141060	Mar 9, 2009	Robert Backstrom
59	45		(38·10153+7)/9	3000000	1546770427	Dec 18, 2008	Serge Batalov
60	45		(86·10148+31)/9	2728500	679331778	Sep 22, 2003	Robert Backstrom
61	45		2·10191+9	3000000	3278687019	Nov 16, 2007	Jo Yeong Uk
62	45		(29·10167+61)/9	3000000	1566598641	Nov 18, 2008	Serge Batalov
63	45		(64·10215+53)/9	43000000	1801021090	Jul 7, 2008	Serge Batalov
64	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	84			(8·10196+1)/9	Apr 27, 2009	Jo Yeong Uk
3	78			(44·10173-71)/9	Mar 5, 2009	Serge Batalov
4	76			(79·10169-7)/9	Oct 1, 2008	Robert Backstrom
5	69			(22·10139-1)/3	May 5, 2005	Greg Childers
6	69			(28·10146-1)/9	Apr 19, 2005	Sinkiti Sibata
7	68			(34·10137+11)/9	Dec 3, 2008	Serge Batalov
8	67			(19·10163+71)/9	Jul 13, 2008	Robert Backstrom
9	66			(5·10159-41)/9	Oct 8, 2007	Jo Yeong Uk
10	65			(22·10163-13)/9	Jul 10, 2008	Robert Backstrom
11	65			(16·10145-43)/9	Apr 19, 2008	Robert Backstrom
12	64			(13·10193+23)/9	Oct 1, 2008	Robert Backstrom
13	62			(23·10184+13)/9	Sep 10, 2008	Sinkiti Sibata
14	62			(14·10145+13)/9	Mar 29, 2008	Jo Yeong Uk
15	62			5·10126+9	Dec 16, 2007	Jo Yeong Uk
16	62			(22·10125-1)/3	Oct 24, 2004	Sander Hoogendoorn
17	61			(8·10178-53)/9	Aug 12, 2008	Serge Batalov
18	61			(4·10148+41)/9	Jan 31, 2005	Samuel Chong
19	61			(46·10174-1)/9	Aug 8, 2008	Serge Batalov
20	61			(8·10120+7)/3	Oct 20, 2007	Jo Yeong Uk
21	60			5·10118-9	Dec 4, 2007	Jo Yeong Uk
22	59			(43·10160-7)/9	Aug 1, 2007	Sinkiti Sibata
23	58			(67·10143+23)/9	Nov 17, 2004	Greg Childers
24	57			(7·10142+11)/9	Apr 28, 2005	Makoto Kamada
25	57			(22·10136+23)/9	Jul 10, 2008	Serge Batalov
26	57			(53·10149-71)/9	Apr 19, 2009	Robert Backstrom
27	56			4·10154+9	Dec 10, 2007	Robert Backstrom
28	56			(5·10113+7)/3	Sep 26, 2007	Jo Yeong Uk
29	55			(4·10143+41)/9	Jan 21, 2005	Samuel Chong
30	55			(41·10109+31)/9	Feb 3, 2009	Erik Branger
31	55			(5·10134-11)/3	Apr 12, 2008	Sinkiti Sibata
32	55			(25·10223-1)/3	Nov 7, 2008	Serge Batalov
33	54			3·10196-1	Oct 3, 2008	Jo Yeong Uk
34	53			(22·10143-31)/9	Jun 27, 2008	Sinkiti Sibata
35	53			(58·10139-13)/9	Jun 29, 2009	Sinkiti Sibata
36	53			(4·10110-31)/9	May 22, 2004	Naoki Yamamoto
37	52			8·10107+3	Aug 9, 2007	Robert Backstrom
38	52			(16·10144-43)/9	Apr 17, 2008	Robert Backstrom
39	52			(19·10163+53)/9	Jun 3, 2008	Jo Yeong Uk
40	52			(88·10152-7)/9	Jun 22, 2006	Sinkiti Sibata
41	51			(10222+17)/9	Jul 9, 2009	Dmitry Domanov
42	51			(64·10122+53)/9	Jul 2, 2003	Robert Backstrom
43	51			(32·10111-41)/9	Nov 22, 2008	Sinkiti Sibata
44	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	84239	(2·1084239+1)/3	Jul 6, 2009	Serge Batalov
2	56545	(19·1056544-1)/9	Mar 13, 2009	Serge Batalov
3	56454	(55·1056453-1)/9	Mar 12, 2009	Serge Batalov
4	55544	(2·1055544+1)/3	Jun 17, 2009	Serge Batalov
5	53718	(1053718-7)/3	Oct 17, 2004	Makoto Kamada
6	53411	(8·1053411+1)/9	Dec 18, 2008	Serge Batalov
7	53050	(19·1053049-1)/9	Mar 9, 2009	Serge Batalov
8	52764	(61·1052763-7)/9	Feb 27, 2009	Serge Batalov
9	43754	(25·1043753-1)/3	Jan 18, 2009	Serge Batalov
10	43272	(61·1043271-7)/9	Jan 2008	Maksym Voznyy
11	40890	(16·1040889-1)/3	Jan 24, 2009	Serge Batalov
12	39606	(2·1039606+1)/3	Jun 20, 2009	Serge Batalov
13	39464	(5·1039464+31)/9	Jan 6, 2009	Serge Batalov
14	38690	(5·1038690+31)/9	Jan 6, 2009	Serge Batalov
15	37597	1037597-9	Jan 2008	Jason Earls
16	35925	1035925-9	Jan 2008	Jason Earls
17	35754	(16·1035753-1)/3	Jan 23, 2009	Serge Batalov
18	31632	(61·1031631-7)/9	Jan 2008	Maksym Voznyy
19	30977	(61·1030976-7)/9	Jan 2008	Maksym Voznyy
20	30178	(1030178-7)/3	Mar 20, 2004	Makoto Kamada
21	26045	1026045-3	Nov 2002	Henri Lifchitz
22	25324	(1025324-7)/3	Feb 7, 2004	Makoto Kamada
23	24549	(1024549-7)/3	Feb 7, 2004	Makoto Kamada
24	24253	(1024253-7)/3	Feb 7, 2004	Makoto Kamada
25	23365	(1023365-7)/3	Feb 7, 2004	Makoto Kamada
26	22973	(1022973+53)/9	Oct 2008	Lelio R Paula
27	22718	(1022718-7)/3	Feb 6, 2004	Makoto Kamada
28	22094	(61·1022093-7)/9	Jan 6, 2008	Maksym Voznyy
29	21873	1021873-3	Nov 2002	Henri Lifchitz
30	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	59136	(28·1059135+53)/9	Nov 19, 2008	Serge Batalov
3	56899	(35·1056898-17)/9	Feb 28, 2009	Serge Batalov
4	50712	1050711+7	Dec 2007	Jason Earls
5	48110	1048109+9	Dec 2007	Jason Earls
6	43187	1043186+9	Dec 2007	Jason Earls
7	40744	(76·1040743-31)/9	Feb 27, 2009	Serge Batalov
8	39856	(38·1039855+61)/9	Oct 15, 2008	Serge Batalov
9	35991	(31·1035990+23)/9	Feb 23, 2009	Serge Batalov
10	35428	(76·1035427-31)/9	Feb 25, 2009	Serge Batalov
11	31811	1031810+9	Oct 14, 2006	Dirk Augustin
12	30222	1030221+7	Nov 2007	Jason Earls
13	27223	(19·1027222+53)/9	Oct 15, 2008	Serge Batalov
14	26928	1026927+3	Dec 2007	Jason Earls
15	26264	(58·1026263-31)/9	Nov 2, 2008	Serge Batalov
16	26195	(67·1026194-13)/9	Oct 15, 2008	Serge Batalov
17	23637	1023636+7	Nov 2007	Jason Earls
18	22049	(13·1022048-7)/3	Feb 23, 2009	Serge Batalov
19	21718	1021717+7	Feb 2004	Thomas Masser
20	20892	7·1020891+9	Jan 12, 2008	Sinkiti Sibata
21	20865	(64·1020864+17)/9	Oct 14, 2008	Serge Batalov
22	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