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A225014
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Number of 7Xn 0..1 arrays with rows unimodal and columns nondecreasing
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1
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8, 64, 372, 1716, 6672, 22716, 69498, 194634, 505912, 1233584, 2845492, 6251596, 13154948, 26635774, 52097267, 98759971, 181971248, 326703424, 572756312, 982365976, 1651162688, 2723729944, 4415408372, 7042481236, 11063492816
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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) = (1/87178291200)*n^14 + (1/958003200)*n^13 + (43/958003200)*n^12 + (103/87091200)*n^11 + (1847/87091200)*n^10 + (7891/29030400)*n^9 + (1560493/609638400)*n^8 + (222427/12441600)*n^7 + (2023297/21772800)*n^6 + (1926401/5443200)*n^5 + (29332549/29937600)*n^4 + (1353853/739200)*n^3 + (183490757/75675600)*n^2 + (363/280)*n + 1
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EXAMPLE
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Some solutions for n=3
..1..1..0....0..0..1....0..1..0....1..0..0....0..0..0....0..0..0....0..0..0
..1..1..0....0..0..1....1..1..0....1..0..0....0..1..0....0..0..0....0..1..0
..1..1..0....0..0..1....1..1..0....1..1..0....1..1..0....0..0..0....0..1..0
..1..1..0....0..0..1....1..1..0....1..1..0....1..1..0....0..0..1....1..1..0
..1..1..0....0..0..1....1..1..1....1..1..0....1..1..0....0..0..1....1..1..0
..1..1..0....0..1..1....1..1..1....1..1..1....1..1..1....0..1..1....1..1..0
..1..1..0....0..1..1....1..1..1....1..1..1....1..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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