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A303097
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Number of n X 3 0..1 arrays with every element equal to 1, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
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1
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1, 15, 77, 486, 2869, 17229, 102952, 616065, 3685099, 22045482, 131879323, 788928513, 4719516650, 28233043741, 168895389127, 1010364108842, 6044188782411, 36157478162593, 216300858973502, 1293952564919109
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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) +9*a(n-2) -14*a(n-3) -28*a(n-4) -6*a(n-5) +32*a(n-6) +10*a(n-7) -2*a(n-8) +32*a(n-9) -32*a(n-11).
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EXAMPLE
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Some solutions for n=5
..0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..1..1
..1..1..0. .1..1..0. .0..0..1. .0..1..1. .1..1..1. .0..0..1. .1..0..1
..1..1..0. .0..1..1. .1..1..0. .0..1..1. .1..0..0. .0..1..1. .0..1..0
..1..0..1. .0..0..1. .0..0..1. .0..0..1. .0..0..1. .1..1..0. .0..0..1
..0..0..0. .1..1..1. .1..1..1. .1..1..1. .1..1..0. .0..0..1. .0..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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