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A225012
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Number of 5 X n 0..1 arrays with rows unimodal and columns nondecreasing.
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1
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6, 36, 161, 581, 1792, 4900, 12174, 27966, 60172, 122464, 237590, 442118, 793092, 1377174, 2322967, 3817351, 6126818, 9624964, 14827487, 22436251, 33394208, 48953224, 70757132, 100942636, 142261016, 198223936, 273277036, 373005396
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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) = (1/3628800)*n^10 + (1/80640)*n^9 + (1/3780)*n^8 + (19/5760)*n^7 + (4633/172800)*n^6 + (331/2304)*n^5 + (191249/362880)*n^4 + (24421/20160)*n^3 + (10897/5600)*n^2 + (137/120)*n + 1 = 1 + n*(n+1)* (n^8 + 44*n^7 + 916*n^6 + 11054*n^5 + 86239*n^4 + 435086*n^3 + 1477404*n^2 + 2918376*n + 4142880)/ 3628800.
Empirical: G.f.: -x*(x^2 - 3*x + 3) *(x^2 - 2*x + 2) *(x^2 - x + 1) *(x^4 - 4*x^3 + 5*x^2 - 2*x + 1) / (x-1)^11. - R. J. Mathar, May 17 2014
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EXAMPLE
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Some solutions for n=3
..0..0..0....0..1..0....0..1..0....1..0..0....0..0..0....0..0..0....0..0..0
..1..0..0....0..1..0....1..1..0....1..1..0....0..0..1....0..0..0....0..1..1
..1..0..0....0..1..0....1..1..1....1..1..0....0..1..1....0..1..0....0..1..1
..1..1..0....0..1..1....1..1..1....1..1..1....0..1..1....0..1..1....1..1..1
..1..1..0....0..1..1....1..1..1....1..1..1....0..1..1....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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