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 A284673 #20 Feb 16 2025 08:33:43
%S A284673 0,1,4,72,45696,93749829120
%N A284673 Number of (undirected) Hamiltonian paths in the n-hypercube graph Q_n.
%H A284673 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HamiltonianPath.html">Hamiltonian Path</a>
%H A284673 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HypercubeGraph.html">Hypercube Graph</a>
%F A284673 a(n) = A091299(n) / 2 for n > 0. - _Andrew Howroyd_, May 09 2017
%t A284673 Table[Total[Flatten[Table[Length[FindPath[HypercubeGraph[n], i, j, {2^n - 1}, All]], {j, 2^n}, {i, j - 1}]]], {n, 0, 4}] (* _Eric W. Weisstein_, Apr 01 2017 *)
%Y A284673 Cf. A091299.
%K A284673 nonn,hard,more
%O A284673 0,3
%A A284673 _Eric W. Weisstein_, Apr 01 2017