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A181200
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a(n) = 0!*1!*2!*...*(n-1)! *(n^2)! *(n*(n-1))^2 / 2*n!*(n+1)!*...*(2*n-1)!
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1
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0, 4, 756, 1729728, 140229804000, 752239365180732000, 419014989521191873479589920, 34623595988556658225393154134784716800, 571228532851873223553288547443139274046846826752000
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OFFSET
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1,2
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COMMENTS
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(Empirical) Number of n X n matrices containing a defective permutation of 1..n*n in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example)
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LINKS
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EXAMPLE
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Some solutions for 3X3
..2..3..5....1..2..5....1..2..6....1..3..4....1..3..4....1..2..4....1..3..5
..4..6..7....3..4..6....3..4..8....2..5..8....2..6..7....2..5..7....2..4..6
..5..8..9....4..7..9....6..7..9....4..6..9....5..7..9....3..6..9....6..7..8
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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