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 A181200 a(n) = 0!*1!*2!*...*(n-1)! *(n^2)! *(n*(n-1))^2 / 2*n!*(n+1)!*...*(2*n-1)! 1
 0, 4, 756, 1729728, 140229804000, 752239365180732000, 419014989521191873479589920, 34623595988556658225393154134784716800, 571228532851873223553288547443139274046846826752000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS (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) Diagonal of A181204 LINKS R. H. Hardin, Table of n, a(n) for n=1..22 EXAMPLE 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 CROSSREFS Sequence in context: A268838 A292306 A319943 * A308141 A284813 A306254 Adjacent sequences:  A181197 A181198 A181199 * A181201 A181202 A181203 KEYWORD nonn AUTHOR R. H. Hardin Oct 10 2010 STATUS approved

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Last modified June 17 05:30 EDT 2021. Contains 345080 sequences. (Running on oeis4.)