This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A014951 #25 Jun 08 2022 15:36:59
%S A014951 1,11,121,253,1331,2783,5819,11891,14641,30613,64009,130801,133837,
%T A014951 161051,273493,336743,558877,704099,768361,849299,1438811,1472207,
%U A014951 1771561,3008423,3078251,3544453,3704173,6147647,6290339,7745089
%N A014951 Positive integers k such that k divides 12^k - 1.
%C A014951 Also, the integers k such that k divides s(k), where s(1)=1 and s(j) = s(j-1) + j*12^(j-1).
%C A014951 From _Alexander Adamchuk_, May 16 2010: (Start)
%C A014951 11 divides a(n) for n > 1.
%C A014951 All powers of 11 are terms.
%C A014951 Prime divisors of a(n) in order of appearance: {11, 23, 47, 3037, 7019, 2663, 5171, 47917, 12973, ...}. (End)
%H A014951 Seiichi Manyama, <a href="/A014951/b014951.txt">Table of n, a(n) for n = 1..100</a>
%t A014951 Join[{1},Select[Range[775*10^4],PowerMod[12,#,#]==1&]] (* _Harvey P. Dale_, Jun 08 2022 *)
%Y A014951 Cf. A015961.
%K A014951 nonn
%O A014951 1,2
%A A014951 _Olivier Gérard_
%E A014951 a(11)-a(30) from _Alexander Adamchuk_, May 16 2010
%E A014951 Edited by _Max Alekseyev_, May 20 2011