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Search: id:A139688
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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. +0
1
1, 4, 40, 1216, 123776, 44030464, 56185705472, 261929007759360, 4520504755804536832 (list; graph; listen)
OFFSET

1,2
CROSSREFS

Sequence in context: A013108 A111846 A102922 this_sequence A072445 A000841 A059918

Adjacent sequences: A139685 A139686 A139687 this_sequence A139689 A139690 A139691

KEYWORD

nonn

AUTHOR

Ron Hardin (rhhardin(AT)att.net), Jun 13 2008

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Last modified December 11 12:57 EST 2009. Contains 170656 sequences.

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