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A326207
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Number of non-Hamiltonian labeled simple graphs with n vertices.
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5
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1, 0, 2, 7, 54, 806, 22690, 1200396, 116759344, 20965139168, 6954959632776, 4363203307789888
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OFFSET
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0,3
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COMMENTS
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A graph is Hamiltonian if it contains a cycle passing through every vertex exactly once.
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LINKS
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FORMULA
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EXAMPLE
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The a(3) = 7 edge sets:
{}
{12}
{13}
{23}
{12,13}
{12,23}
{13,23}
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MATHEMATICA
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Table[Length[Select[Subsets[Subsets[Range[n], {2}]], FindHamiltonianCycle[Graph[Range[n], #]]=={}&]], {n, 0, 4}] (* Mathematica 8.0+ *)
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CROSSREFS
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The directed version is A326220 (with loops) or A326216 (without loops).
Simple graphs with a Hamiltonian cycle are A326208.
Simple graphs without a Hamiltonian path are A326205.
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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