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 A234365 #29 Jun 27 2025 23:19:52
%S A234365 2,32,3168,926208,598579200,723105792000,1464887918592000,
%T A234365 4610898301943808000,21308780838537658368000,
%U A234365 138404291567096011161600000,1220304754650628950589440000000,14197926030549494380143575040000000,212919452788134597593544586690560000000,4034887005978635554837074343530332160000000
%N A234365 Number of directed Hamiltonian cycles in the complete tripartite graph K_{n,n,n}.
%H A234365 Zlatko Damijanic, <a href="/A234365/b234365.txt">Table of n, a(n) for n = 1..160</a>
%H A234365 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CompleteTripartiteGraph.html">Complete Tripartite Graph</a>.
%H A234365 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HamiltonianCycle.html">Hamiltonian Cycle</a>.
%F A234365 a(n) = n!^2 * (n-1)! * A141147(n) = n!^2 * (n-1)! * (A000172(n-1)+A000172(n)) * 2 / 3.
%F A234365 a(n) = 2*A307924(n). - _Andrew Howroyd_, Nov 10 2024
%t A234365 Table[n!^2 (n - 1)! 2^n HypergeometricPFQ[{n, (1 - n)/2, -n/2}, {1, 1}, 1], {n, 10}] (* _Eric W. Weisstein_, Apr 26 2017 *)
%Y A234365 Cf. A000172, A141147, A307924.
%K A234365 nonn
%O A234365 1,1
%A A234365 _Max Alekseyev_, Dec 25 2013