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A369143
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Number of labeled simple graphs with n edges and n vertices such that it is not possible to choose a different vertex from each edge (non-choosable).
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10
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0, 0, 0, 0, 0, 30, 1335, 47460, 1651230, 59636640, 2284113762, 93498908580, 4099070635935, 192365988161490, 9646654985111430, 515736895712230192, 29321225548502776980, 1768139644819077541440, 112805126206185257070660, 7595507651522103787077270, 538504704005397535690160274
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OFFSET
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0,6
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LINKS
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FORMULA
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EXAMPLE
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The term a(5) = 30 counts all permutations of the graph {{1,2},{1,3},{1,4},{2,3},{2,4}}.
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MATHEMATICA
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Table[Length[Select[Subsets[Subsets[Range[n], {2}], {n}], Length[Select[Tuples[#], UnsameQ@@#&]]==0&]], {n, 0, 5}]
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CROSSREFS
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The version without the choice condition is A116508, covering A367863.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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