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 A234624 #17 Feb 16 2025 08:33:21 %S A234624 0,1,312,3228524,6198979538330,3366323909717796339009 %N A234624 Number of (undirected) cycles in the n X n rook graph. %H A234624 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GraphCycle.html">Graph Cycle</a> %H A234624 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RookGraph.html">Rook Graph</a> %Y A234624 Main diagonal of A286418. %Y A234624 Cf. A269561, A096970. %K A234624 nonn,more %O A234624 1,3 %A A234624 _Eric W. Weisstein_, Dec 28 2013 %E A234624 a(6) from _Andrew Howroyd_, May 08 2017