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A215767
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Number of undirected labeled graphs on n nodes with exactly 7 cycle graphs as connected components.
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2
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1, 28, 462, 6300, 82929, 1128204, 16187314, 245722477, 3944372432, 66863837040, 1194908786890, 22468992674310, 443708326841383, 9184432111987960, 198909290886899005, 4499373643453767540, 106128250525908452226, 2606280798870785902866, 66541442123879872392375
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OFFSET
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7,2
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LINKS
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MAPLE
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T:= proc(n, k) option remember; `if`(k<0 or k>n, 0, `if`(n=0, 1,
add(binomial(n-1, i)*T(n-1-i, k-1)*ceil(i!/2), i=0..n-k)))
end:
a:= n-> T(n, 7):
seq (a(n), n=7..25);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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