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A251023
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Number of (n+1)X(3+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements
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1
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1966, 8207, 20608, 51347, 118871, 272547, 608267, 1356939, 3017800, 6755296, 15194024, 34402203, 78257659, 178761713, 409448316, 939731942, 2159479782, 4966624315, 11428488961, 26305947749, 60561558048, 139440168208
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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) = 8*a(n-1) -25*a(n-2) +35*a(n-3) -7*a(n-4) -49*a(n-5) +77*a(n-6) -55*a(n-7) +20*a(n-8) -3*a(n-9) for n>14
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EXAMPLE
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Some solutions for n=4
..0..0..3..3....0..0..2..2....0..0..2..3....0..0..1..2....3..3..3..3
..1..0..0..0....0..0..0..0....1..0..1..0....0..0..1..1....0..0..0..0
..1..0..0..0....1..0..0..0....1..0..1..0....0..0..0..0....2..1..1..1
..2..1..1..1....1..0..0..0....1..0..1..0....0..0..0..0....2..0..0..0
..3..0..0..0....2..1..0..0....3..2..1..0....3..2..2..1....3..1..1..0
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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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