A128157 a(n) = least k such that the remainder when 17^k is divided by k is n.

2, 3, 7, 13, 142, 11, 25, 9, 10, 299, 57, 203, 46, 69, 274, 613024059983, 19, 7099195, 30, 21, 134, 24065, 38, 133, 28, 27, 205, 155591, 33, 20452755522967, 49, 165, 35, 391, 99, 94271801, 198, 39, 70, 23353, 62, 2759, 55, 1623, 122, 22649, 665, 1591398755

Offset: 1

Author

Alexander Adamchuk, Feb 16 2007

Keywords

• hard
• nonn

Links

• Robert G. Wilson v, Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found

Crossrefs

Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128154, A128155, A128156, A128158, A128159, A128160, A128149, A128150.

Programs

Mathematica

t = Table[0, {10000} ]; k = 1; While[ k < 4500000000, a = PowerMod[17, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t

Extensions

More terms from Hagen von Eitzen, Jul 31 2009

a(338) = 7615772967 = 3 * 11 * 230780999 [From Daniel Morel, May 18 2010]

a(100) = 36706228199, a(154) = 10618746241, a(444) = 10700153359, a(616) = 7969009427, a(720) = 11004291191, a(984) = 11601377453 [From Daniel Morel, Jun 15 2010]

a(184) = 16808380397, a(508) = 34412778035 [From Daniel Morel, Nov 05 2010]