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A298489
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Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 7 king-move adjacent elements, with upper left element zero.
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1
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4, 13, 20, 27, 43, 70, 106, 169, 276, 444, 720, 1183, 1947, 3207, 5311, 8826, 14681, 24474, 40897, 68419, 114596, 192212, 322715, 542258, 911962, 1534860, 2584781, 4355511, 7343271, 12386305, 20901774, 35285703, 59589460, 100666009, 170109263
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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) -2*a(n-2) +3*a(n-3) -9*a(n-4) +4*a(n-5) -a(n-6) +9*a(n-7) -3*a(n-8) -a(n-9) -4*a(n-10) +2*a(n-11) for n>12
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EXAMPLE
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Some solutions for n=9
..0..0..0. .0..1..0. .0..1..0. .0..1..1. .0..1..0. .0..1..0. .0..0..0
..1..1..1. .1..1..0. .1..0..1. .0..1..0. .1..0..0. .1..1..0. .1..1..1
..1..0..1. .1..1..0. .1..0..0. .1..0..1. .0..1..1. .1..1..0. .1..0..1
..1..1..1. .0..1..0. .1..0..0. .1..0..0. .1..0..1. .0..1..0. .1..1..1
..1..1..1. .1..0..1. .1..0..1. .1..0..0. .0..1..1. .1..1..0. .1..1..1
..1..0..1. .0..1..0. .0..0..1. .1..0..1. .1..0..0. .1..1..0. .1..0..1
..1..1..1. .1..0..1. .0..0..1. .0..1..0. .0..1..0. .0..1..0. .1..1..1
..0..0..0. .0..1..0. .1..0..1. .1..0..1. .1..0..0. .1..0..1. .0..0..0
..0..1..0. .0..1..1. .0..0..1. .1..0..0. .0..1..1. .0..1..0. .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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