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 A143246 #27 Feb 22 2025 20:10:24 %S A143246 0,2,0,12,0,2144,0,9277152,0,934520913216,0,2152453777211211412,0, %T A143246 112252999240982874562527216,0,131765033045251672652319572331061144,0, %U A143246 3467852755777932367855581588111341658695967892,0 %N A143246 Number of (directed) Hamiltonian circuits in the n X n grid graph. %H A143246 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a> %H A143246 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HamiltonianCycle.html">Hamiltonian Cycle</a> %H A143246 Ed Wynn, <a href="http://arxiv.org/abs/1402.0545">Enumeration of nonisomorphic Hamiltonian cycles on square grid graphs</a>, arXiv preprint arXiv:1402.0545 [math.CO], 2014. %H A143246 <a href="/index/Gra#graphs">Index entries for sequences related to graphs, Hamiltonian</a> %Y A143246 Cf. A003763 (number of undirected cycles on 2n X 2n grid graph). %Y A143246 Cf. A222065 (A222065(n) = a(2n)). %Y A143246 Cf. A120443. %K A143246 nonn %O A143246 1,2 %A A143246 _Eric W. Weisstein_, Aug 01 2008