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 A129349 #26 Feb 16 2025 08:33:05 %S A129349 0,2,32,6432,19497984,1109403156480,1380937534541660160 %N A129349 Number of directed Hamiltonian circuits in the n-triangular graph. %H A129349 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HamiltonianCycle.html">Hamiltonian Cycle</a> %H A129349 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TriangularGraph.html">Triangular Graph</a> %K A129349 nonn,more %O A129349 2,2 %A A129349 _Eric W. Weisstein_, Apr 10 2007 %E A129349 a(6) from _Alois P. Heinz_, Nov 29 2010 %E A129349 a(7)-a(8) from _Eric W. Weisstein_, Mar 31 2014 %E A129349 Missing factor of 2 applied to a(8) by _Eric W. Weisstein_, Apr 08 2014 %E A129349 Offset corrected by _Eric W. Weisstein_, May 06 2019