A093376 Number of labeled n-vertex graphs with 2-components and without isolated vertices(1-components).

0, 0, 1, 0, 3, 40, 585, 15708, 760277, 67656960, 11346344145, 3648840170580, 2277220167519825, 2780207051899228224, 6675377730807161508041, 31633731603265107184483860, 296598264243770222308892404305

Offset

0,5

Links

Table of n, a(n) for n=0..16.

Formula

E.g.f. exp(-x)*(1-exp(-x^2/2))*Sum(2^binomial(n, 2)*x^n/n!, n=0..infinity). Inverse binomial transform of A093351().

Crossrefs

Cf. A006129, A093351, A093352.

Sequence in context: A331795 A005724 A215196 * A051571 A019654 A361069

Adjacent sequences: A093373 A093374 A093375 * A093377 A093378 A093379

Keyword

nonn

Author

Goran Kilibarda, Vladeta Jovovic, Apr 28 2004

Status

approved