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A093351 Number of labeled n-vertex graphs with a 2-component. 3
0, 0, 1, 3, 9, 65, 885, 20769, 904799, 75119535, 12059144775, 3777502008115, 2321770382163177, 2810098818045932049, 6714509196242295683053, 31734155232117923771498025, 297105206555826680431032956415 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

FORMULA

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

CROSSREFS

Cf. A093352.

Sequence in context: A144525 A087673 A046239 * A018543 A026090 A119751

Adjacent sequences:  A093348 A093349 A093350 * A093352 A093353 A093354

KEYWORD

nonn

AUTHOR

Goran Kilibarda, Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 26 2004

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Last modified February 17 10:05 EST 2012. Contains 206009 sequences.