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A235407
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Number of (n+1)X(2+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing rowwise and nonincreasing columnwise
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1
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44, 172, 704, 2302, 7617, 21707, 62070, 160219, 413728, 994013, 2386992, 5442827, 12403299, 27224435, 59728771, 127521907, 272186909, 569643759, 1192017901, 2459436721, 5074257282, 10364928156, 21172231949, 42946541188, 87117681967
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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) = 4*a(n-1) +15*a(n-2) -78*a(n-3) -84*a(n-4) +696*a(n-5) +112*a(n-6) -3760*a(n-7) +1218*a(n-8) +13704*a(n-9) -8862*a(n-10) -35508*a(n-11) +32060*a(n-12) +67024*a(n-13) -76668*a(n-14) -92568*a(n-15) +131079*a(n-16) +91860*a(n-17) -164969*a(n-18) -61582*a(n-19) +153888*a(n-20) +22296*a(n-21) -105420*a(n-22) +2424*a(n-23) +51632*a(n-24) -7808*a(n-25) -17136*a(n-26) +4320*a(n-27) +3456*a(n-28) -1152*a(n-29) -320*a(n-30) +128*a(n-31)
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EXAMPLE
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Some solutions for n=4
..0..0..0....1..0..0....0..1..0....1..0..0....1..0..1....1..0..1....0..0..1
..1..0..0....0..0..1....1..0..1....1..0..0....1..1..0....0..1..0....1..0..0
..0..1..0....1..1..0....0..1..0....1..1..0....0..1..0....0..1..0....1..0..1
..1..1..0....1..0..0....1..1..0....0..1..0....1..1..0....1..1..0....1..1..0
..1..1..0....1..1..0....1..1..0....1..1..1....0..1..0....1..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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