A093351 Number of labeled n-vertex graphs with a 2-component.

0, 0, 1, 3, 9, 65, 885, 20769, 904799, 75119535, 12059144775, 3777502008115, 2321770382163177, 2810098818045932049, 6714509196242295683053, 31734155232117923771498025, 297105206555826680431032956415

Offset: 0

Author

Goran Kilibarda, Vladeta Jovovic, Apr 26 2004

Keywords

• nonn

Crossrefs

Cf. A093352.

Formula

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