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%I #5 Aug 23 2012 21:06:37
%S 1,28,462,6300,82929,1128204,16187314,245722477,3944372432,
%T 66863837040,1194908786890,22468992674310,443708326841383,
%U 9184432111987960,198909290886899005,4499373643453767540,106128250525908452226,2606280798870785902866,66541442123879872392375
%N Number of undirected labeled graphs on n nodes with exactly 7 cycle graphs as connected components.
%H Alois P. Heinz, <a href="/A215767/b215767.txt">Table of n, a(n) for n = 7..170</a>
%p T:= proc(n, k) option remember; `if`(k<0 or k>n, 0, `if`(n=0, 1,
%p add(binomial(n-1, i)*T(n-1-i, k-1)*ceil(i!/2), i=0..n-k)))
%p end:
%p a:= n-> T(n, 7):
%p seq (a(n), n=7..25);
%Y Column k=7 of A215771.
%K nonn
%O 7,2
%A _Alois P. Heinz_, Aug 23 2012
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