A014956 Positive integers k such that k divides 14^k - 1.

1, 13, 169, 2041, 2197, 26533, 28561, 114413, 320437, 344929, 371293, 1487369, 4165681, 4484077, 4826809, 17962841, 19335797, 24355253, 50308609, 54153853, 58293001, 62748517, 77457601, 233516933, 249302027, 251365361, 316618289

Offset: 1

Author

Olivier Gérard

Keywords

• nonn

Comments

Also, positive integers k such that k divides A014929(k).

13 divides a(n) for n > 1. All powers of 13 are terms. All a(n) that are not powers of 13 are divisible either by 157 or 677 or both. - Alexander Adamchuk, May 14 2010

Prime divisors of a(n) in order of appearance: {13, 157, 677, 11933, 122147, 52807, ...}. - Alexander Adamchuk, May 16 2010

Crossrefs

Cf. A067945, A014945, A067946, A014946, A067947, A014949, A068382, A014950, A068383, A014951, A116621, A177805, A014957, A177807, A128358, A128360.

Cf. A177914, A128394.

Programs

Mathematica

Join[{1}, Select[Range[2000000], PowerMod[14, #, #] == 1 &]] (* Robert Price, Mar 31 2020 *)

Extensions

2 more terms from R. J. Mathar, Mar 05 2008

a(8)-a(23) from Alexander Adamchuk, May 14 2010

a(24)-a(44) from Alexander Adamchuk, May 16 2010

Edited by Max Alekseyev, Sep 10 2011