A139688 - OEIS

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A139688

Half the number of n X n binary matrices with row sum i equal to column sum i, i in 1..n.

1, 4, 40, 1216, 123776, 44030464, 56185705472, 261929007759360, 4520504755804536832 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	LINKS	`Table of n, a(n) for n=1..9.`
	CROSSREFS	`Sequence in context: A173945 A111846 A102922 * A197356 A072445 A000841` `Adjacent sequences: A139685 A139686 A139687 * A139689 A139690 A139691`
	KEYWORD	`nonn`
	AUTHOR	`R. H. Hardin, Jun 13 2008`
	STATUS	`approved`

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Last modified May 25 19:59 EDT 2013. Contains 225649 sequences.