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 A267653 #8 Jan 20 2016 04:19:30 %S A267653 1,1,2,6,21,111,818,9825,195759,6622127,368949015 %N A267653 Number of unlabeled, connected graphs on n vertices which have no induced subgraph isomorphic to an R-graph. %C A267653 The R-graph has 6 vertices. 4 vertices form a cycle and both the other two vertices are adjacent to a single one of those 4. %H A267653 F. Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version e8699da. %Y A267653 Cf. A079570, the same for the cricket graph (like an R-graph, but with a triangle instead of a 4-cycle). %K A267653 nonn,more %O A267653 1,3 %A A267653 _Falk Hüffner_, Jan 19 2016