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 A297487 #14 Feb 16 2025 08:33:52
%S A297487 3,14,342,5256,252360,7950960,582346800,30400755840,3055726477440,
%T A297487 234650484230400,30479146156166400,3193083216360576000,
%U A297487 515174657767010841600,69927761804930559129600,13622234004598726450944000,2307722078006148475736064000
%N A297487 Number of maximal matchings in the complete tripartite graph K_{n,n,n}.
%H A297487 Andrew Howroyd, <a href="/A297487/b297487.txt">Table of n, a(n) for n = 1..100</a>
%H A297487 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CompleteTripartiteGraph.html">Complete Tripartite Graph</a>
%H A297487 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Matching.html">Matching</a>
%H A297487 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MaximalIndependentEdgeSet.html">Maximal Independent Edge Set</a>
%t A297487 Table[3 n! HypergeometricPFQ[{(1 - n)/2, -n, -n/2}, {1}, -4] - If[Mod[n, 2] == 0, 2 (n!/(n/2)!)^3, 0], {n, 20}]
%o A297487 (PARI) a(n)={if(n%2==0, binomial(n, n/2)*(n/2)!, 0)^3 + sum(k=0, (n-1)\2, 3*binomial(n, k)^2*binomial(n, 2*k)*binomial(2*k, k)*k!^2*(n-k)!)} \\ _Andrew Howroyd_, Dec 30 2017
%Y A297487 Cf. A293075.
%K A297487 nonn
%O A297487 1,1
%A A297487 _Eric W. Weisstein_, Dec 30 2017
%E A297487 Terms a(6) and beyond from _Andrew Howroyd_, Dec 30 2017