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A224413
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Number of 6Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing
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1
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64, 972, 4636, 13440, 31710, 68282, 139638, 275766, 530583, 999049, 1844709, 3342831, 5946316, 10384152, 17805490, 29986574, 49622914, 80735424, 129226948, 203634878, 316136662, 483878162, 730710330, 1089437826, 1604704333
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = (1/479001600)*n^12 + (1/7257600)*n^11 + (199/43545600)*n^10 + (1/10752)*n^9 + (19951/14515200)*n^8 + (5143/345600)*n^7 + (6148357/43545600)*n^6 + (3015961/1451520)*n^5 + (128983289/10886400)*n^4 + (40193333/604800)*n^3 + (444089893/1663200)*n^2 - (4351/20)*n - 222 for n>4
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EXAMPLE
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Some solutions for n=3
..1..1..0....0..1..1....1..1..1....1..0..0....1..1..0....1..1..0....0..0..0
..1..0..0....1..1..1....1..1..0....1..0..0....1..0..0....1..0..0....1..0..0
..0..1..0....1..1..1....1..1..1....0..0..0....0..0..0....1..0..0....0..1..1
..1..0..0....1..1..0....1..1..1....0..0..0....1..0..0....1..0..0....1..1..0
..0..0..1....1..0..0....1..1..0....1..1..0....1..1..1....1..1..0....1..0..0
..1..1..0....0..0..0....1..1..0....1..1..1....1..1..1....1..0..0....0..0..0
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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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