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A091479 Number of graphs with n nodes. Nodes and edges labeled each from their own label set. 2
1, 1, 2, 16, 1957, 9864101, 3554627472076, 138879579704209680022, 828772446866981044847857913441, 1011182700521015817607065606491025592595137, 325166909258549255903203528672831330994640286650913570126 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..30

FORMULA

a(n) = A000522(A000217(n-1)). - Gerald McGarvey, Nov 17 2007

PROG

(PARI) a(n)={binomial(n, 2)!*sum(k=0, binomial(n, 2), 1/k!)} \\ Andrew Howroyd, Feb 12 2020

CROSSREFS

Row sums of A091478.

Cf. A006125.

Cf. A000217, A000522.

Sequence in context: A337070 A326974 A060597 * A016031 A331691 A001309

Adjacent sequences:  A091476 A091477 A091478 * A091480 A091481 A091482

KEYWORD

nonn

AUTHOR

Christian G. Bower, Jan 13 2004

EXTENSIONS

a(0)=1 prepended and terms a(10) and beyond from Andrew Howroyd, Feb 12 2020

STATUS

approved

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Last modified March 4 14:37 EST 2021. Contains 341796 sequences. (Running on oeis4.)