A014951 Positive integers k such that k divides 12^k - 1.

1, 11, 121, 253, 1331, 2783, 5819, 11891, 14641, 30613, 64009, 130801, 133837, 161051, 273493, 336743, 558877, 704099, 768361, 849299, 1438811, 1472207, 1771561, 3008423, 3078251, 3544453, 3704173, 6147647, 6290339, 7745089

Offset: 1

Author

Olivier Gérard

Keywords

• nonn

Comments

Also, the integers k such that k divides s(k), where s(1)=1 and s(j) = s(j-1) + j*12^(j-1).

From Alexander Adamchuk, May 16 2010: (Start)

11 divides a(n) for n > 1.

All powers of 11 are terms.

Prime divisors of a(n) in order of appearance: {11, 23, 47, 3037, 7019, 2663, 5171, 47917, 12973, ...}. (End)

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A015961.

Programs

Mathematica

Join[{1},Select[Range[775*10^4],PowerMod[12,#,#]==1&]] (* Harvey P. Dale, Jun 08 2022 *)

Extensions

a(11)-a(30) from Alexander Adamchuk, May 16 2010

Edited by Max Alekseyev, May 20 2011