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 A036724 #5 Jul 08 2025 21:55:13 %S A036724 1,1,3,18,109,768,5652,43618,346353,2816526,23321925,196005552, %T A036724 1667527836,14333190427,124283998707,1085847441828,9549523972105, %U A036724 84471264138366,751042470499425,6708237169875867,60164133936171522 %N A036724 G.f. satisfies A(x) = 1 + x*cycle_index(G,A(x)) where G = cyclic group of order 2 generated by (1,2)(3,4)(5,6). %Y A036724 Cf. A036717-A036723. %K A036724 nonn %O A036724 0,3 %A A036724 _N. J. A. Sloane_