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A054940 Number of connected labeled graphs with n nodes and an odd number of edges. 0
0, 1, 1, 22, 352, 13412, 932768, 125776816, 33148125376, 17248244478848, 17820828772662272, 36677298103403269504, 150636101324831804975104, 1235824405515221870758956032, 20263840468865240117261288526848 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..15.

V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.

FORMULA

a(n)=(A001187(n)+(-1)^n*A000142(n-1))/2.

CROSSREFS

Cf. A054939.

Sequence in context: A103722 A100904 A036738 * A016265 A208458 A016263

Adjacent sequences:  A054937 A054938 A054939 * A054941 A054942 A054943

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 24 2000

EXTENSIONS

More terms from Vladeta Jovovic, Jul 17 2000

STATUS

approved

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Last modified May 25 23:22 EDT 2013. Contains 225649 sequences.