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 A287512 #15 Feb 16 2025 08:33:46 %S A287512 0,0,1,4,20,113,818,8584,135637,3263785,115779695,5855248060 %N A287512 Number of simple perfect non-bipartite graphs on n vertices. %H A287512 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BipartiteGraph.html">Bipartite Graph</a> %H A287512 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PefectGraph.html">Perfect Graph</a> %H A287512 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SimpleGraph.html">Simple Graph</a> %F A287512 a(n) = A052431(n) - A033995(n), since all bipartite graphs are perfect. - _Falk Hüffner_, Aug 10 2017 %Y A287512 Cf. A033995, A052431. %K A287512 nonn,more %O A287512 1,4 %A A287512 _Eric W. Weisstein_, May 26 2017 %E A287512 a(11)-a(12) from formula by _Falk Hüffner_, Aug 10 2017