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 A243559 #16 Sep 23 2020 15:59:51 %S A243559 1,1,2,5,9,26,80,340,1690,11432,101142,1228608,20329150 %N A243559 Number of simple connected graphs with n nodes that have no subgraph isomorphic to bull graph or K_4. %C A243559 K_4 is the complete graph with four vertices. %H A243559 Travis Hoppe and Anna Petrone, <a href="https://github.com/thoppe/Encyclopedia-of-Finite-Graphs">Encyclopedia of Finite Graphs</a> %H A243559 T. Hoppe and A. Petrone, <a href="http://arxiv.org/abs/1408.3644">Integer sequence discovery from small graphs</a>, arXiv preprint arXiv:1408.3644, 2014 %H A243559 F. Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version 29e68fa. %Y A243559 Cf. A244427 (no bull subgraphs), A079574 (K_4 free graphs). %K A243559 nonn,more %O A243559 1,3 %A A243559 _Travis Hoppe_ and _Anna Petrone_, Jun 06 2014 %E A243559 a(11)-a(13) added using tinygraph by _Falk Hüffner_, Sep 23 2020