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 A145270 #17 Feb 21 2025 05:34:05 %S A145270 0,0,0,0,0,1,13,207,5143,189195,10663766,989251266,163746458178, %T A145270 50329965610911 %N A145270 Number of simple connected nonplanar graphs on n nodes. %H A145270 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConnectedGraph.html">Connected Graph</a> %H A145270 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NonplanarGraph.html">Nonplanar Graph</a> %H A145270 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SimpleGraph.html">Simple Graph</a> %F A145270 a(n) = A001349(n) - A003094(n). %Y A145270 Cf. A145269. %K A145270 nonn,more %O A145270 0,7 %A A145270 _Eric W. Weisstein_, Oct 05 2008 %E A145270 Edited by _Max Alekseyev_, Sep 18 2009 %E A145270 a(12) added by _Max Alekseyev_, Aug 17 2015 %E A145270 a(13) from _Max Alekseyev_, Feb 20 2025