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A283124
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Number of nX2 0..1 arrays with no 1 equal to more than two of its horizontal and vertical neighbors.
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3
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4, 16, 57, 209, 768, 2816, 10329, 37889, 138980, 509792, 1869969, 6859233, 25160352, 92290688, 338531473, 1241767297, 4554926628, 16707926384, 61286344841, 224804441777, 824605173856, 3024734241792, 11095027685417, 40697671100929
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OFFSET
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1,1
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COMMENTS
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Column 2 of A283130.
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..210
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FORMULA
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Empirical: a(n) = 3*a(n-1) +2*a(n-2) +2*a(n-3) -a(n-4) -a(n-5).
Empirical: G.f.: -x*(x+2)*(x^3-x-2)/(1-3*x-2*x^2-2*x^3+x^4+x^5) . - R. J. Mathar, Mar 02 2017
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EXAMPLE
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Some solutions for n=4
..0..1. .1..1. .1..1. .1..0. .1..0. .1..1. .1..0. .0..1. .0..0. .1..0
..1..1. .0..0. .0..0. .0..1. .1..1. .1..0. .0..1. .0..1. .0..1. .0..0
..0..0. .1..1. .0..1. .0..0. .0..0. .1..0. .1..0. .1..0. .1..1. .1..0
..1..1. .0..1. .1..1. .0..1. .0..0. .1..1. .0..1. .1..0. .0..0. .1..0
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CROSSREFS
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Cf. A283130.
Sequence in context: A197674 A297220 A297375 * A282393 A034514 A263851
Adjacent sequences: A283121 A283122 A283123 * A283125 A283126 A283127
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Mar 01 2017
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STATUS
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approved
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