cp's OEIS Frontend

A215770 Number of undirected labeled graphs on n nodes with exactly 10 cycle graphs as connected components.

%I A215770 #5 Aug 23 2012 21:07:01
%S A215770 1,55,1705,40755,864864,17597580,357501430,7394469940,157152692697,
%T A215770 3447161882307,78214593177825,1837521249630885,44711396042691202,
%U A215770 1126629665018647306,29386149075365532659,792965839703648696250,22122127578168037696705,637598054468679136895205
%N A215770 Number of undirected labeled graphs on n nodes with exactly 10 cycle graphs as connected components.
%H A215770 Alois P. Heinz, <a href="/A215770/b215770.txt">Table of n, a(n) for n = 10..170</a>
%p A215770 T:= proc(n, k) option remember; `if`(k<0 or k>n, 0, `if`(n=0, 1,
%p A215770       add(binomial(n-1, i)*T(n-1-i, k-1)*ceil(i!/2), i=0..n-k)))
%p A215770     end:
%p A215770 a:= n-> T(n, 10):
%p A215770 seq (a(n), n=10..30);
%Y A215770 Column k=10 of A215771.
%K A215770 nonn
%O A215770 10,2
%A A215770 _Alois P. Heinz_, Aug 23 2012