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 A218462 #19 Feb 16 2025 08:33:18 %S A218462 1,6,101,10413,11557799 %N A218462 Number of simple perfect matching graphs on 2n nodes. %C A218462 Perfect matchings exist only for graphs with an even number of nodes. %H A218462 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PerfectMatching.html">Perfect Matching</a> %F A218462 a(n) = A218463(n) + A287652(n). - _Eric W. Weisstein_, May 29 2017 %F A218462 a(n) = A286951(2*n, n). - _Andrew Howroyd_, Sep 05 2019 %Y A218462 Cf. A218463 (connected simple perfect matching graphs). %Y A218462 Cf. A287652 (disconnected simple perfect matching graphs). %Y A218462 Cf. A286951. %K A218462 nonn,more %O A218462 1,2 %A A218462 _Eric W. Weisstein_, Mar 26 2013