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A301881
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Number of nX5 0..1 arrays with every element equal to 0, 1 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.
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1
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8, 35, 125, 510, 1961, 7869, 31173, 124795, 497909, 1992271, 7963325, 31857711, 127402805, 509641959, 2038421709, 8153897359, 32614779749, 130460538967, 521837435069, 2087359218591, 8349408257621, 33397695880743, 133590605170989
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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) = 3*a(n-1) +14*a(n-2) -34*a(n-3) -56*a(n-4) +120*a(n-5) +64*a(n-6) -128*a(n-7) for n>9
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EXAMPLE
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Some solutions for n=5
..0..1..0..0..1. .0..0..1..1..1. .0..1..1..1..0. .0..0..1..0..1
..0..1..1..1..0. .1..0..1..0..0. .0..1..0..1..0. .1..1..1..1..0
..0..1..1..1..1. .1..0..1..1..0. .0..0..0..1..0. .0..1..1..1..0
..1..0..1..0..1. .1..0..0..1..0. .1..1..1..1..1. .1..0..0..1..0
..1..0..0..0..1. .1..1..0..1..1. .1..0..1..0..1. .1..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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