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 A177906 #15 Jun 06 2021 09:03:50
%S A177906 1,5,1555,9673655,24181805,90993505,200928005,28298980055,36850702555,
%T A177906 62488609555,141377087255,150435008905,367279622065,2256331679135,
%U A177906 7521049172905,18802586659555,24599612913355,54706615318945
%N A177906 Numbers k such that k^3 divides 6^(k^2) - 1.
%C A177906 5 divides a(n) for n > 1.
%C A177906 Prime divisors of a(n) in order of their appearance are {5, 311, 6221, 15551, 18198701, 40185601, ...}.
%C A177906 From there on, the list is no longer increasing; it continues with 23698201, 90917741, 236192683, 93307, 311021, ... - _M. F. Hasler_, Oct 21 2012
%o A177906 (PARI) is_A177906(n)=Mod(6,n^3)^(n^2)==1 \\ _M. F. Hasler_, Oct 21 2012
%Y A177906 Cf. A014946 (k divides 6^k-1), A127106 (k^2 divides 6^k-1).
%Y A177906 Cf. A129211, A129212, A177905, A177907, A127102, A177909, A177243.
%Y A177906 Cf. A177911, A177912, A177913, A177914, A177915, A177916, A177917, A177918, A177919, A177920.
%K A177906 nonn
%O A177906 1,2
%A A177906 _Alexander Adamchuk_, May 16 2010
%E A177906 More terms from _Max Alekseyev_, Oct 02 2010