Search for the least odd prime p such that (np - 1)/(n - 1) is prime

n:
search limit:
185
200000
269
100000
281
100000
380
100000
384
100000
385
100000
396
100000
452
100000
465
100000
n:
search limit:
511
100000
574
100000
598
100000
601
100000
631
100000
632
100000
636
100000
711
100000
759
100000
n:
search limit:
771
100000
795
100000
866
100000
881
100000
938
100000
951
100000
956
100000
1015
100000

After performing trial factoring on the given base, I will proceed with a PRP test on the exponents for which factors were not found.
You can use srsieve2 with parameter --outputfactors=results.txt to output a file with factors.
You can alse trial factoring with mfaktc-gr (may miss factors) and find more information at https://www.mersenneforum.org/showthread.php?t=24901.
Trial factoring with PARI is not suggested, but you can still use the following code to search for small factors:
TF(base, p, limit=10^14) = forprimestep(q=1, limit, 2*p, if(Mod(base, q)^p==1, return(q))); 0;
base=185; forprime(p=100000, 101000, t=TF(base, p, 10^12); if(t, print("R[", base, "]", p, " has a factor: ", t)));


-> submit TF results here <-
-> if you find a new generalized repunit (PRP) prime, submit it to PRP Top Records <-

nA128164(n)
23
33
40
53
63
75
83
90
1019
1117
123
135
143
153
160
173
1825667
1919
203
213
225
235
243
250
267
273
285
295
305
317
320
333
3413
35313
360
3713
383
39349
405
413
421319
435
445
4519
467
47127
4819
490
503
514229
52103
5311
543
5517
567
573
5841
593
607
617
623
635
640
6519
663
6719
685
693
7029
713
727
735
745
753
7641
773
783
795
803
810
8223
835
8417
855
8611
877
8861
893
903
914421
92439
937
945
957
963343
9717
9813
993
1000
1013
10259
10319
10497
1053
106149
10717
108449
10917
1103
1113
11279
11323
11429
1157
11659
1173
1185
1193
1205
1210
1225
12343
124599
1250
1267
1275
1287
1295
13037
1313
13247
13313
1345
1351171
136227
13711
1383
139163
14079
1413
1421231
1433
1440
1455
1467
1473
1481201
1497
1503
15113
152270217
1533
1545
1553
1567
15717
1587
15913
1607
1613
1623
1637
1643
1655
166137
1673
1683
1690
17017
171181
1725
1733
1743251
1755
1763
1775
178347
17919
1807
18117
182167
183223
18416703
185>200000 [Searching...]
1867
18737
1883
1893
19013
19117
1923
1935
1943
19511
1960
19731
1985
199577
20017807
201271
20237
2033
2045
20519
2063
20713
2085
2093
21019819
21141
21211
213137
214191
2153
2160
217281
2183
21913
2207
2217
2225
223239
22411
2250
226127
2275
228461
22911
2305333
2313
232953
233113
23461
2357
2363
2377
2387
2395
240109
24117
24219
2430
2443331
2453
2463
24717
24841
2495
250127
2517
252541
25319
2545
2555
2560
25723
25811
2592011
2605
26131
262197
2635
2647
2655
2663
26713
26811
269>100000
270241
27141
2723
27337
2745
2755
27631
2775
2783
2793
2807
281>100000
2827
28329
2842473
2855
28613
2873
2883
2890
2903
29113
2925
2933
2947
29517
29641
29717
29853
299113
3007
301193
30237
3037
3045
305617
30626407
30753
3085
3093
31043
31136497
3123373
313109
3143
31517
31641
317157
3181193
31911
3207
321647
322227
323283
3240
32531
32626713
3275
32867
3293
33079
33125033
3323
3339743
33479
33517
3363
3375
338157
33911
3405
3417
3423
3430
3443
345103
34667
347337
3483
3497
3507
3513
3525
3537
35479
35511
356419
3573
3581499
3595
3602609
3610
362199
3637
36417
36511
36611
367239
36817
3693
37019
37115527
37267
3735
37471
3751993
3761223
37743
3783
37917
380>100000
3813
38213
3833
384>100000 [Hibou is searching...]
385>100000 [Hibou is searching...]
38683
38731
38831
38911
39011
3919623
3923
3935
39461637
3953
396>100000
3975
3983
3997
4000
401127
4023
403167
4043
4053
40613
407457
4085
40943
41017
4111061
41213
41331
4143
415139
4163
4175
4185
41917
42061
42171
422983
42317
42419
42561
4263
427127
42897
42953
43041
43117
43237
43341
4343
4353
4367
4375
4387
4395
44067
4410
44213
44347
44437
445109
44619
4473
4485
44919
4507
45129
452>100000
4533
4541217
4553
4563
4575
458769
4595
46029
4617
46231
463313
4647
465>100000
4667
46711
46823
4695987
47031
471293
47217
473127
4745
475383
4763
47743
4787
4795
48011
48119
482401
48379
4840
48599523
48613
4879967
488337
4893
4905
49131
4925
493131
494263
4953
49647
497127
498503
4994691
5003
501683
502149
5035
50411
5055
50617
50713
5082003
50919
51067
511>100000
5123
51317
5145
5152243
51671
5172887
5183
5195
520269
52119
52220183
5237
52467
5253
52643
52717
5285
5290
5303
5313
5321373
5333
53411
535331
5366653
5373
5385
5395
5403
5418951
54213
54311
54413
54541
5461609
54719
5487
54931
5505
5513
55213
55313
5543
55541
55643
5575
558317
55973
5603
56161
562379
5635
564101
56579
5663
5673
5685
56931
57012907
57117
5723
57319
574>100000
575997
5760
577109
578521
5793
580139
58119
5823
5837
5843
58513
58643
58729
588811
5891187
5903881
5917
59211
59383
5945
595191
59641
59717
598>100000
5997
600337
601>100000
602233
6033
6045
6053
606229
607887
60861
6093
61013
6117
6123
613131
61413
6151613
61689
6175
61831
61911
620487
6213
6227
62353
6243
6250
6263
62729
62829
62932233
630199
631>100000
632>100000
633103
63413
6353
636>100000
6375
63859
63931
64018913
641113
6423
64313
6443
6455
6467
6477
6483347
64943987
6505
65119
652463
65317
65411
6557
65617
6577
658257
65929
6607
661223
6625
66323
664191
66543
66637
66761
6683
669137
67018617
6713
672547
67319
67461
675449
6760
6773
678127
6795
68037
6817
68241
6835483
68422573
685127
6863
68729
68817
68913
69043
69162903
69243
69341189
6945
695881
6963
697101
6987
6995
7007
7013
7025897
703101
704101
705397
70631
707137
70813
70911
7107
711>100000
712191
71374897
7145
715389
7164133
7177
7183709
719113
7203
721457
722439
72331
724827
725229
7263
727347
7283
7290
73013
73115427
732661
73367
7347
7353
73619
737479
738139
7395087
74017
741349
74247
7433
74413
7455
74631
7473
748383
749167
7505
751967
75232833
753439
754229
7553
75611
75737
758127
759>100000
7607
7613
7623
763197
764131
7655
76611
76731
7683
76913
7705
771>100000
7725
7733
77431
775103
7767
77747
77811
77961
7804003
78159
7823
78343
7840
7853
786181
78711
7881213
789389
790281
7911873
7923
7935
794157
795>100000
79631
79719
7983
79953
8007
8013
8027
80343
8045
8055
80611
80719
808421
809107
81019
81119
8123
813197
81441
8151583
816353
81719
8183
8193
82012043
82143
8227
823107
8245
8253
82667
8273
828937
829211
830487
831101
83241
833137
83423
83517
8363
8375
838587
8393
84019
8410
8427
843269
8444289
845433
8463
847383
84843
849241
85079
85113
852541
85313
8545
8553
8567
8573
85853
85929
8603
86154181
86213
8637
8643
865877
866>100000
86719
8685
86919
8707
87173
87210093
873383
87411
8753
8761039
87731
8783
8793373
8805
881>100000
88213
883131
88423
88541
886613
8871201
88819
889367
8903
891997
892997
893587
8943
8954507
896127
8973
8984951
8993
9000
90159
90219
90331
90423
905223
90683
9077331
908919
90943
9101613
9113
9127
9137
914223
9153
9161993
9172269
9183
9195
9203
921199
9225987
92331
92453
9252089
9267
9273
92813
92953
93013
9317
93220431
93379
93497
93579
93653
93761
938>100000
93959
9407
9417
9425
94311
944199
945109
946113
9477
94844579
9491283
9503
951>100000
95213
953131
9545
955691
956>100000
957167
958331
9593
9603
9610
96237
96368821
96437
9651061
96647
9675
9685
9693
97079
97119
9724937
97311
9743
975179
97617
977211
978277
9795
98017
9813
98217
983199
9847
985461
98617
9873
98819
9891321
9903
99131
9923
9933
9944723
99559
99614629
99723
9987
999107
10000
10013
10023
100311
1004431
100589087
100613
10073
100831
10095
101019
10113
10125749
101337
1014241
1015>100000
10163
1017643
10182473
101913
10203
102173
10223
102319
10240