A067209 - OEIS

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A067209

Number of n X n 0..1 matrices with all row and column sums equal.

2, 4, 14, 140, 4322, 434542, 144109562, 165431317452, 654143160457922 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	EXAMPLE	`Some solutions for n=5` `..1..1..0..0..1....0..0..1..0..1....0..1..0..1..1....1..1..0..1..0` `..1..1..0..0..1....1..1..0..0..0....1..1..0..0..1....1..0..1..1..0` `..0..0..1..1..1....1..0..0..1..0....1..1..1..0..0....1..0..1..0..1` `..1..0..1..1..0....0..1..1..0..0....0..0..1..1..1....0..1..0..1..1` `..0..1..1..1..0....0..0..0..1..1....1..0..1..1..0....0..1..1..0..1`
	CROSSREFS	`Sequence in context: A193520 A102897 A001527 * A134040 A061291 A166105` `Adjacent sequences: A067206 A067207 A067208 * A067210 A067211 A067212`
	KEYWORD	`nonn`
	AUTHOR	`R. H. Hardin (rhhardin(AT)att.net), Feb 20 2002`
	EXTENSIONS	`Added one term and example - R. H. Hardin, Jan 05, 2012`

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Last modified February 16 09:56 EST 2012. Contains 205904 sequences.