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 A036723 #5 Jul 08 2025 21:55:06 %S A036723 1,1,2,8,30,135,622,3032,15134,77506,403780,2135588,11430910,61815916, %T A036723 337193808,1853183376,10251612034,57037706410,318965425380, %U A036723 1791842232154,10107161112356,57221612791015,325045726349906,1852055247196164 %N A036723 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). %Y A036723 Cf. A036717-A036722. %K A036723 nonn %O A036723 0,3 %A A036723 _N. J. A. Sloane_