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A306124
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Number of n X 3 0..1 arrays with every element unequal to 0, 1, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.
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1
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3, 7, 9, 19, 39, 73, 147, 319, 681, 1451, 3127, 6789, 14887, 32963, 73569, 165355, 374119, 851749, 1949959, 4486007, 10364533, 24034895, 55913671, 130430861, 304967127, 714466543, 1676614357, 3939963499, 9269602859, 21830156705
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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) -a(n-3) -7*a(n-4) +4*a(n-5) -4*a(n-6) -7*a(n-8) +9*a(n-9) +14*a(n-10) +11*a(n-11) -7*a(n-12) -6*a(n-13).
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EXAMPLE
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Some solutions for n=5
..0..1..1. .0..0..0. .0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..1..1
..0..0..1. .1..0..0. .1..1..1. .0..0..0. .1..1..1. .0..0..1. .1..1..1
..1..1..1. .1..0..1. .0..0..1. .0..0..1. .1..1..1. .0..0..0. .0..0..1
..0..1..1. .0..0..1. .0..1..1. .0..1..1. .1..1..1. .0..0..0. .1..1..1
..0..0..1. .0..0..0. .1..1..1. .1..1..1. .0..1..1. .0..0..0. .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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