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A225013
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Number of 6Xn 0..1 arrays with rows unimodal and columns nondecreasing
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1
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7, 49, 252, 1036, 3612, 11088, 30738, 78354, 186142, 416394, 884236, 1794196, 3497248, 6577474, 11980667, 21201211, 36548573, 61520899, 101320712, 163556776, 259187048, 403770544, 619111172, 935394436, 1393938716, 2050706932
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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 + (187/43545600)*n^10 + (13/161280)*n^9 + (14671/14515200)*n^8 + (3043/345600)*n^7 + (2380201/43545600)*n^6 + (347911/1451520)*n^5 + (8129699/10886400)*n^4 + (923183/604800)*n^3 + (913741/415800)*n^2 + (49/40)*n + 1
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EXAMPLE
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Some solutions for n=3
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..0....1..1..0
..0..1..0....0..0..0....0..1..0....0..0..0....0..0..0....0..1..1....1..1..0
..0..1..0....1..0..0....0..1..1....0..1..0....1..0..0....0..1..1....1..1..0
..0..1..0....1..1..0....0..1..1....0..1..0....1..0..0....0..1..1....1..1..0
..1..1..0....1..1..0....1..1..1....0..1..0....1..0..0....0..1..1....1..1..1
..1..1..1....1..1..0....1..1..1....0..1..0....1..0..0....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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STATUS
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approved
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