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 A130058 #13 Jun 08 2021 02:24:43
%S A130058 1,67,89,133,199,331,617,793,881,5281,8911,11419,13333,22177,23585,
%T A130058 26467,35113,35839,38897,40657,44023,54913,65869,67849,70819,92929,
%U A130058 105469,107185,114247,124279,144673,153253,159259,185329,196945,225589
%N A130058 Numbers m such that k = m*23^2 divides 3^(k-1) - 2^(k-1).
%C A130058 All prime p>3 divide 3^(p-1) - 2^(p-1). It appears that 1 and 529 = 23^2 are the only perfect squares in A073631. Most terms of A073631 are squarefree. First 50 nonsquarefree terms of A073631 are the multiples of 23^2.
%C A130058 Conjecture: All nonsquarefree terms of A073631 are the multiples of 23^2.
%C A130058 Prime terms are listed in A130059. Note that the many terms (namely, 1, 133, 793, 8911, 13333, 22177, 26467, 38897, 44023, 54913, 65869, ...) also belong to A073631.
%t A130058 Do[ k=n*23^2; f=PowerMod[ 3, k-1, k ] - PowerMod[ 2, k-1, k ]; If[ IntegerQ[ f/k ], Print[ n ] ], {n,1,1000000} ]
%Y A130058 Cf. A073631, A001047, A130059.
%K A130058 nonn
%O A130058 1,2
%A A130058 _Alexander Adamchuk_, May 04 2007