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A371868
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Number of connected chordal bipartite graphs on n unlabeled vertices.
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2
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1, 1, 1, 3, 5, 16, 41, 154, 560, 2550, 12404, 69536, 428698, 2947229, 22288540, 185226859, 1682006569, 16635022967, 178525323313
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refs;
listen;
history;
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internal format)
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OFFSET
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1,4
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COMMENTS
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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.
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LINKS
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EXAMPLE
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The 3 examples for n=4 are the 4-cycle, the star, and the path.
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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STATUS
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approved
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