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A282856
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Number of nX2 0..1 arrays with no 1 equal to more than one of its horizontal, vertical and antidiagonal neighbors.
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1
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4, 11, 31, 89, 251, 715, 2028, 5761, 16358, 46452, 131910, 374581, 1063696, 3020560, 8577449, 24357268, 69167021, 196412696, 557750593, 1583837157, 4497601906, 12771782030, 36267864414, 102989386002, 292457628811, 830488149997
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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) = a(n-1) +4*a(n-2) +3*a(n-3) +a(n-4) +a(n-5).
Empirical: G.f.: -x*(1+x)*(x^3+x^2+3*x+4)/(-1+x+4*x^2+3*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
..1..0. .0..1. .0..1. .0..0. .1..0. .1..1. .0..0. .0..1. .1..0. .0..0
..1..0. .1..0. .0..0. .1..0. .0..0. .0..0. .0..0. .1..0. .1..0. .0..0
..0..0. .0..0. .1..0. .1..0. .1..0. .1..0. .1..1. .0..1. .0..0. .1..0
..1..1. .1..1. .0..0. .0..0. .0..1. .0..1. .0..0. .0..0. .1..0. .0..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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