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A223768
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Number of nX6 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing
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1
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22, 169, 607, 1601, 3699, 8007, 16742, 34096, 67890, 132115, 251110, 465910, 843960, 1493505, 2584666, 4379914, 7277630, 11873716, 19047873, 30083272, 46831011, 71934087, 109129744, 163654129, 242779358, 356520541, 518559236, 747440414
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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 - (1/15966720)*n^11 + (23/8709120)*n^10 - (59/1451520)*n^9 + (22591/14515200)*n^8 - (1159/53760)*n^7 + (713737/1741824)*n^6 - (1665749/290304)*n^5 + (795178259/10886400)*n^4 - (220668799/362880)*n^3 + (73774259/20790)*n^2 - (340682581/27720)*n + 20228 for n>8
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EXAMPLE
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Some solutions for n=3
..0..1..0..0..0..0....1..0..0..0..0..0....0..1..0..0..0..0....0..1..1..1..1..0
..1..1..1..1..0..0....1..1..1..0..0..0....0..1..1..1..0..0....0..1..1..1..1..1
..0..1..1..1..1..1....0..1..1..1..1..0....1..1..1..1..1..1....0..0..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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