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 A242790 #17 Feb 16 2025 08:33:22 %S A242790 1,1,2,4,11,39,165,967,7684,87012,1410465,32640019 %N A242790 Number of connected diamond-free graphs on n nodes. %C A242790 An equivalent definition: Number of simple connected graphs with n nodes that are have no subgraph isomorphic to the diamond graph or the complete graph K_4. This is the same because a graph contains a diamond as a subgraph iff it contains a diamond or K_4 as induced subgraph. - _Falk Hüffner_, Jan 11 2015 %H A242790 Travis Hoppe and Anna Petrone, <a href="https://github.com/thoppe/Encyclopedia-of-Finite-Graphs">Encyclopedia of Finite Graphs</a> %H A242790 Falk Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version ece94ef. %H A242790 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DiamondGraph.html">Diamond Graph</a> %Y A242790 Cf. A077269 (connected squarefree graphs). %Y A242790 Cf. also A242790 (diamond free graphs), A079574 (K_4 free graphs). %K A242790 nonn,more %O A242790 1,3 %A A242790 _Travis Hoppe_ and _Anna Petrone_, May 22 2014 %E A242790 Entry revised by _N. J. A. Sloane_, Jan 11 2016 %E A242790 a(11) and a(12) added using tinygraph by _Falk Hüffner_, Jan 15 2016