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 A362904 #12 Jun 25 2023 08:55:32 %S A362904 1,8,43,176,611,1864,5161,13184,31532,71264,153444,316608,629236, %T A362904 1209312,2255324,4093056,7246690,12542736,21262582,35359456,57767766, %U A362904 92832784,146908290,229169792,352721676,536076640,805132548,1195771840,1757278132 %N A362904 Number of nonisomorphic ordered triples of involutions on a (2n)-set that pairwise commute. %C A362904 Two involutions x,y commute if x*y = y*x. Isomorphism is up to permutation of the elements of the (2n)-set. a(n) also gives the value for a (2n+1)-set. %H A362904 Andrew Howroyd, <a href="/A362904/b362904.txt">Table of n, a(n) for n = 0..1000</a> %H A362904 <a href="/index/Rec#order_26">Index entries for linear recurrences with constant coefficients</a>, signature (8, -21, 0, 106, -176, -70, 512, -435, -392, 1001, -512, -580, 1120, -580, -512, 1001, -392, -435, 512, -70, -176, 106, 0, -21, 8, -1). %F A362904 G.f.: 1/((1 - x)^16*(1 + x)^8*(1 + x^2)). %o A362904 (PARI) C(3,30) \\ C(k,n) defined in A362903. %Y A362904 Column k=3 of A362903. %K A362904 nonn %O A362904 0,2 %A A362904 _Andrew Howroyd_, May 11 2023