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A282125
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Number of n X 2 0..2 arrays with no element unequal to more than four of its king-move neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
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1
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0, 0, 30, 412, 4018, 35472, 296062, 2378276, 18602538, 142686584, 1078094998, 8049085452, 59514821186, 436531302624, 3180302488110, 23036382105332, 166033195371866, 1191480270802248, 8517590180994246, 60683797705011932
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OFFSET
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1,3
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LINKS
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FORMULA
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Empirical: a(n) = 14*a(n-1) - 57*a(n-2) + 88*a(n-3) - 256*a(n-4) + 240*a(n-5) - 320*a(n-6) + 256*a(n-7) - 64*a(n-8).
Empirical g.f.: 2*x^3*(3 - 2*x + 4*x^2)*(5 + 2*x - 12*x^2) / (1 - 7*x + 4*x^2 - 16*x^3 + 8*x^4)^2. - Colin Barker, Feb 20 2019
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EXAMPLE
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Some solutions for n=4:
..0..0. .0..1. .0..1. .0..1. .0..0. .0..0. .0..1. .0..0. .0..1. .0..0
..0..1. .0..1. .0..1. .1..1. .1..2. .1..2. .0..2. .1..0. .0..2. .1..0
..2..0. .2..1. .0..2. .1..0. .2..2. .2..2. .0..0. .2..1. .1..1. .0..0
..1..2. .0..1. .0..1. .2..1. .2..0. .0..0. .0..2. .1..1. .2..2. .2..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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