A054939 - OEIS

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A054939

Number of connected labeled graphs with n nodes and an even number of edges.

1, 0, 3, 16, 376, 13292, 933488, 125771776, 33148165696, 17248244115968, 17820828776291072, 36677298103363352704, 150636101324832283976704, 1235824405515221864531935232, 20263840468865240117348466818048 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	LINKS	`V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.`
	FORMULA	`a(n)=(A001187(n)+(-1)^(n-1)*A000142(n-1))/2.`
	CROSSREFS	`Sequence in context: A013923 A053466 A005031 * A081782 A176299 A081780` `Adjacent sequences: A054936 A054937 A054938 * A054940 A054941 A054942`
	KEYWORD	`nonn,easy`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), May 24 2000`
	EXTENSIONS	`More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Jul 17 2000`

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Last modified February 14 20:38 EST 2012. Contains 205663 sequences.