A093855 Triangle read by rows: T(n,m) = number of T_0-multigraphs with n edges and m vertices(n>=2, 3<=m<=2*n).

3, 12, 7, 44, 80, 0, 12, 111, 440, 840, 630, 0, 18, 234, 1532, 6048, 13692, 13440, 0, 0, 25, 441, 4270, 26740, 106792, 248696, 277200, 75600, 0, 0, 33, 768, 10360, 92940, 557322, 2169416, 5158512, 6617520, 3326400, 0, 0, 0

Offset

2,1

Links

Table of n, a(n) for n=2..43.

Formula

E.g.f.: (1+x)*exp(-x-x^2/2*y/(1-y))*Sum((1-y)^(-binomial(n, 2))*x^n/n!, n=0..infinity).

Example

3,12; 7,44,80,0; 12,111,440,840,630,0; 18,234,1532,6048,13692,13440,0,0; 25,441,4270,26740,106792,248696,277200,75600,0,0;
33,768,10360,92940,557322,2169416,5158512,6617520,3326400,0,0,0; ...

Crossrefs

Sequence in context: A304566 A291156 A175046 * A355338 A344112 A337203

Adjacent sequences: A093852 A093853 A093854 * A093856 A093857 A093858

Keyword

nonn,tabf

Author

Goran Kilibarda, Vladeta Jovovic, May 21 2004

Status

approved