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 A319896 #14 Jan 11 2020 15:57:47 %S A319896 0,1,0,3,31,595,33931,6020479,3613415171 %N A319896 Number of connected non-regular multigraphs with n nodes of degree up to n. %C A319896 Multigraphs are loopless. %C A319896 Terms computed using nauty traces. %H A319896 Brendan McKay and Adolfo Piperno, <a href="http://pallini.di.uniroma1.it">Nauty traces</a> %F A319896 a(n) = A289988(n) - A319897(n). %Y A319896 Cf. A289988, A289986, A319897. %K A319896 nonn,more,hard %O A319896 0,4 %A A319896 _Natan Arie Consigli_, Sep 30 2018