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