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 A177913 #11 Jun 06 2021 06:02:20
%S A177913 1,2,3,4,6,10,12,14,20,28,30,34,42,60,68,70,84,102,110,114,140,170,
%T A177913 183,204,210,220,222,228,238,330,340,366,406,420,444,476,510,570,660,
%U A177913 714,732,770,798,812,820,876,930,942,1010,1020,1110,1140,1190,1218,1428
%N A177913 Numbers k such that k^3 divides 13^(k^2) - 1.
%H A177913 Robert Price, <a href="/A177913/b177913.txt">Table of n, a(n) for n = 1..2236</a>
%t A177913 Join[{1}, Select[Range[3000000], PowerMod[13, #^2, #^3] == 1 &]] (* _Robert Price_, Mar 31 2020 *)
%Y A177913 Cf. A128393 (k^2 divides 13^k-1).
%Y A177913 Cf. A129211, A129212, A177905, A127106, A177907, A127102, A177909, A177243.
%Y A177913 Cf. A177911, A177912, A177913, A177914, A177915, A177916, A177917, A177918, A177919, A177920.
%K A177913 nonn
%O A177913 1,2
%A A177913 _Alexander Adamchuk_, May 14 2010