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A326223
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Number of non-Hamiltonian unlabeled n-vertex digraphs (with loops).
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8
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OFFSET
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0,3
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COMMENTS
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A digraph is Hamiltonian if it contains a directed cycle passing through every vertex exactly once.
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LINKS
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EXAMPLE
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Non-isomorphic representatives of the a(2) = 7 digraph edge-sets:
{}
{11}
{12}
{11,12}
{11,21}
{11,22}
{11,12,22}
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CROSSREFS
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The undirected case is A246446 (without loops) or A326239 (with loops).
Hamiltonian unlabeled digraphs are A326226.
Unlabeled digraphs not containing a Hamiltonian path are A326224.
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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