Generalized Cullen primes   n bn + 1

b   Values of   n
3   2, 8, 32, 54, 114, 414, 1400, 1850, 2848, 4874, 7268, 19290, 337590, 1183414  [1200000] *
4   1, 3, 7, 33, 67, 223, 663, 912, 1383, 3777, 3972, 10669, 48375  [250000] ×
5   1242, 18390  [379575]
6   1, 2, 91, 185, 387, 488, 747, 800, 9901, 10115, 12043, 13118, 30981, 51496  [200000] =
7   34, 1980, 9898  [255681]
8   5, 17, 23, 1911, 20855, 35945, 42816  [166666] 749130 o
9   2, 12382, 27608, 31330, 117852  [222431]
10   1, 3, 9, 21, 363, 2161, 4839, 49521, 105994, 207777  [270026]
11   10  [600000] o
12   1, 8, 247, 3610, 4775, 19789, 187895  [254519]
13   None  [1000000] ÷
14   3, 5, 6, 9, 33, 45, 243, 252, 1798, 2429, 5686, 12509, 42545  [246922]
15   8, 14, 44, 154, 274, 694, 17426, 59430  [136149]
16   1, 3, 55, 81, 223, 1227, 3012, 3301  [125000] +
17   19650, 236418  [281261]
18   1, 3, 21, 23, 842, 1683, 3401, 16839, 49963, 60239, 150940, 155928  [203597]
19   6460  [305777] o
20   3, 6207, 8076, 22356, 151456  [219976]
21   2, 8, 26, 67100  [274099]
22   1, 15, 189, 814, 19909, 72207  [137649]
23   4330, 89350  [177567]
24   2, 8, 368  [134188]
25    [500000] 2805222 ÷
26   117, 3143, 3886, 7763, 64020, 88900  [147626]
27   2, 56, 23454  [215413] 259738 *
28   1, 48, 468, 2655, 3741, 49930  [200618]
29   None  [500000] ÷
30   1, 2, 3, 7, 14, 17, 39, 79, 87, 99, 128, 169, 221, 252, 307, 3646, 6115, 19617, 49718  [101757]
31   82960  [174855] o
32   5  [100000] ÷
33   2, 632, 1840, 91848  [131715]
34   25, 33, 103, 195, 303, 415  [126648]
35   304, 19116  [117225]
36   1, 2, 3, 8, 191, 1256, 6788, 22195, 23335, 29481  [90181] 191013
37   36  [259437]
38   3, 1209  [141911]
39   368, 402, 36592  [209347]
40   1, 202  [50675] 74844
41    [500000] 1806676 ÷
42   1, 2, 11, 20, 8301, 14421, 25849, 37208, 52296  [170000] ×
43   390  [158019]
44   53  [90664]
45   2, 8, 84  [120049]
46   1, 813, 1576  [89009]
47   None  [500000] ÷
48   3, 9, 14, 79, 114, 182, 9328, 13569, 60261  [93537]
49   None  [500000] ÷
50   9665, 11844, 92278  [104798]
51   62, 1376, 10108, 29726, 65816, 136628  [212349]
52   1, 168, 38559  [158573]
53    [500000] 1341174 ÷
54   3, 8, 29, 11270  [75855]
55   None  [497236] ÷
56   1072, 31265  [125830]
57   234, 470, 1670, 1898  [119337]
58   1, 3, 34, 181, 252, 1135, 2139, 4510  [197120]
59   220, 74460  [149849]
60   1, 9, 13, 113, 167, 202, 445, 518, 3522, 7423, 70615  [87580]
61   142, 76710  [146157]
62   1295, 7107, 43379  [154473]
63   8, 50, 54398  [81489]
64   3, 399, 7813, 14253  [80000] ÷
65   16990  [126417]
66   1, 2, 158, 257, 1016, 2543, 3396, 3801, 81778  [106152]
67   474, 52932  [171857]
68   129897 [151037] ÷
69   None  [470690] ÷
70   1, 3, 13, 5928, 10585, 18157, 20155, 36534  [74775]
71   13948  [158622] ×
72   1, 2, 35, 119, 274, 607, 3185, 14360, 25201  [96313]
73   None  [464214] ÷
74   3, 15, 26770  [131086]
75   2  [110363]
76   1161, 5401, 15516  [106662]
77   12198  [131667]
78   1, 25, 105, 254, 10671  [58516]
79   682156  [682156] ÷
80   5, 273, 3273, 23074, 59871  [99392]
81   350, 73272   126042, 178192 [280000] *
82   1, 1407, 22515  [110750]
83   1242  [163911]
84   26, 59215  [70976]
85   186, 1134, 39496  [131529]
86   3, 17, 45, 267, 117172  [159482]
87   2, 118, 34150  [224455]
88   1, 411, 1191  [123155]
89   298  [281849]
90   14, 514, 587, 27419, 49527  [159281]
91   101670  [256545]
92   9, 252, 3900, 9215  [195230]
93   2, 3332, 5642, 183500  [219271]
94   775, 1207, 3277, 11169  [108252]
95   202, 370, 18258  [121773]
96   1, 2, 3, 8, 16350, 43895, 143717  [167204]
97   1374  [138893]
98   63, 622, 1125, 4517, 25830, 174885  [203858]
99   2, 332, 21868, 26982, 31328, 138846  [182529]
100   1, 427, 2475, 21369, 72048, 98035  [165295] 316903

* b=3: [166817] 166800 - 1200000 done by P. Minovic
× b=4: [108769] 108770 - 250000 done by S. Harvey, 250001 - 670000 reserved by B. Koen
= b=6: [123669] 123670 - 200000 done by G. Reynolds
o b=8: [106574] 106755 - 166666 done by S. Harvey, 166666 - 800000 reserved by S. Batalov
o b=11: [214215] 214216 - 600000 done by S. Batalov
÷ b=13: [159581] 159500 - 252039 done by P. Minovic, 1 - 999940 done by PrimeGrid, 999941 - 2000000 reserved by PrimeGrid
+ b=16: [75360] 75361 - 125000 done by S. Harvey
o b=19: [305777] 305778 - 500000 reserved by S. Batalov
÷ b=25: [315153] 1 - 999996 done by PrimeGrid, 2805222 found by Prime Grid
* b=27: [215413] 215414 - 300000 reserved by T. Ritschel
÷ b=29: [349419] 1 - 999988 done by PrimeGrid
o b=31: [174855] 174856 - 420000 reserved by S. Batalov
÷ b=32: [45790] 45791 - 100000 done by S. Harvey, 100001 - 500000 reserved by PrimeGrid
÷ b=41: [67025] 67026 - 100031 done by P. Minovic, 1 - 999966 done by PrimeGrid, 1806676 found by PrimeGrid (H. Okazaki)
× b=42: [62691] 62692 - 170000 done by B. Koen
÷ b=47: [171707] 1 - 999834 done by PrimeGrid
÷ b=49: [201927] 1 - 999876 done by PrimeGrid
÷ b=53: [103895] 1 - 999928 done by PrimeGrid, 1341174 found by PrimeGrid
÷ b=55: [65583] 65584 - 100001 done by P. Minovic, 1 - 999966 done by PrimeGrid
÷ b=64: [35234] 35235 - 80000 done by S. Harvey, 1 - 199923 done by PrimeGrid, 199924 - 500000 reserved by PrimeGrid
÷ b=68: [118162] 1 - 151037 done by PrimeGrid
÷ b=69: [68009] 68010 - 100100 done by P. Minovic, 1 - 999870 done by PrimeGrid
× b=71: [126795] 126796 - 158622 done by B. Koen
÷ b=73: [157121] 1 - 999988 done by PrimeGrid
÷ b=79: [149301] 1 - 692232 done by PrimeGrid, 692233 - 1000000 reserved by PrimeGrid
* b=81: [81809] 81810 - 280000 done by T. Ritschel, 280001 - 300000 reserved by T. Ritschel

Last modified November 23, 2019. Günter Löh