A215769 Number of undirected labeled graphs on n nodes with exactly 9 cycle graphs as connected components.

1, 45, 1155, 23265, 425139, 7606599, 138177325, 2587238940, 50238819917, 1014260971581, 21309355619799, 465938970674775, 10598414480600407, 250610854305313887, 6155065643528547592, 156866857683142545246, 4144501278635384568055, 113404466183331483985825

Offset

9,2

Links

Alois P. Heinz, Table of n, a(n) for n = 9..170

Maple

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, 9):
seq (a(n), n=9..30);

Crossrefs

Column k=9 of A215771.

Sequence in context: A268870 A049447 A327510 * A320822 A229796 A143400

Adjacent sequences: A215766 A215767 A215768 * A215770 A215771 A215772

Keyword

nonn

Author

Alois P. Heinz, Aug 23 2012

Status

approved