

A371868


Number of connected chordal bipartite graphs on n unlabeled vertices.


2



1, 1, 1, 3, 5, 16, 41, 154, 560, 2550, 12404, 69536, 428698, 2947229, 22288540, 185226859, 1682006569, 16635022967, 178525323313
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OFFSET

1,4


COMMENTS

A chordal bipartite graph is a bipartite graph with no induced cycles longer than 4cycles. Note that this is not the same as a bipartite graph which is chordal, as that would exclude all cycles.


LINKS



EXAMPLE

The 3 examples for n=4 are the 4cycle, the star, and the path.


CROSSREFS



KEYWORD

nonn,hard,more


AUTHOR



STATUS

approved



