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 A286949 #12 Feb 16 2025 08:33:45 %S A286949 0,1,2,5,13,43,182,1082,9979,147043,3419289,119265551 %N A286949 Number of perfect disconnected simple graphs on n nodes. %H A286949 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DisconnectedGraph.html">Disconnected Graph</a> %H A286949 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PerfectGraph.html">Perfect Graph</a> %F A286949 a(n) = A052431(n) - A052433(n). %e A286949 \bar K_2; (1 graph) %e A286949 \bar K_3, K_1 \cup K_2; (2 graphs) %e A286949 \bar K_4, P_2 \cup 2 K_1, P_3 \cup K_1, C_3 \cup K_1, 2P_2 (5 graphs) %e A286949 Here, \bar indicates a graph complement and \cup a (disjoint) graph union. %K A286949 nonn,more %O A286949 1,3 %A A286949 _Eric W. Weisstein_, May 17 2017