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 A371868 #8 Apr 10 2024 09:34:21 %S A371868 1,1,1,3,5,16,41,154,560,2550,12404,69536,428698,2947229,22288540, %T A371868 185226859,1682006569,16635022967,178525323313 %N A371868 Number of connected chordal bipartite graphs on n unlabeled vertices. %C A371868 A chordal bipartite graph is a bipartite graph with no induced cycles longer than 4-cycles. Note that this is not the same as a bipartite graph which is chordal, as that would exclude all cycles. %H A371868 Brendan McKay, <a href="https://users.cecs.anu.edu.au/~bdm/nauty/">nauty software </a> that can generate these graphs. %H A371868 Wikipedia, <a href="https://en.wikipedia.org/wiki/Chordal_bipartite_graph">Chordal bipartite graph</a>. %e A371868 The 3 examples for n=4 are the 4-cycle, the star, and the path. %Y A371868 Cf. A371867, A371869. %K A371868 nonn,hard,more %O A371868 1,4 %A A371868 _Brendan McKay_, Apr 09 2024