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A303619
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Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
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1
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1, 12, 38, 148, 616, 2520, 10288, 42100, 172268, 704776, 2883500, 11797636, 48268920, 197487780, 808003420, 3305872824, 13525678764, 55339088836, 226414867352, 926355911364, 3790101263196, 15506855855704, 63444895485516
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 5*a(n-1) -5*a(n-2) +8*a(n-3) -12*a(n-4) +4*a(n-5) -4*a(n-6) for n>8
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EXAMPLE
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Some solutions for n=5
..0..1..1. .0..1..0. .0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..0
..1..1..1. .1..1..1. .0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..1
..0..1..0. .0..1..1. .1..0..0. .1..1..1. .0..0..1. .1..0..0. .0..0..1
..0..1..1. .1..1..1. .0..0..0. .1..1..0. .1..0..0. .0..0..0. .1..0..0
..1..1..0. .1..1..1. .0..0..1. .1..1..1. .0..0..1. .1..0..1. .0..0..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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