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A067210
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Number of n X n 0..2 matrices with all row and column sums equal.
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1
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3, 9, 87, 5673, 2577513, 8459809773, 207495141083975, 39125696231091082665, 57899300601363050181107733, 683382115404724657577266518831159, 65156055488094891194179319045960728827635, 50704966066306827486637758645370695372532720829085
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OFFSET
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1,1
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LINKS
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EXAMPLE
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Some solutions for n=4
..1..1..0..1....0..0..2..1....2..0..1..1....2..0..2..2....2..1..1..0
..0..2..1..0....1..1..1..0....0..1..2..1....1..2..1..2....0..2..0..2
..2..0..0..1....2..0..0..1....2..1..0..1....1..2..2..1....1..0..2..1
..0..0..2..1....0..2..0..1....0..2..1..1....2..2..1..1....1..1..1..1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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added one term and example - R. H. Hardin, Jan 05 2012
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STATUS
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approved
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