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A281982
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Number of n X 2 0..1 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, 2, 16, 88, 432, 2008, 8992, 39200, 167552, 705440, 2934784, 12091264, 49416448, 200598912, 809606656, 3251253760, 12999782400, 51779385856, 205542608896, 813446920192, 3210502631424, 12640023828480, 49653803819008
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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) = 8*a(n-1) - 20*a(n-2) + 24*a(n-3) - 36*a(n-4) + 16*a(n-5) - 16*a(n-6).
Empirical g.f.: 2*x^3 / (1 - 4*x + 2*x^2 - 4*x^3)^2. - Colin Barker, Feb 20 2019
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EXAMPLE
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Some solutions for n=4:
..0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..1. .0..0
..1..0. .1..1. .0..0. .0..0. .1..0. .0..1. .0..1. .1..0. .0..0. .0..1
..0..0. .1..0. .0..1. .1..0. .0..0. .0..0. .0..0. .0..0. .0..1. .0..0
..0..0. .1..1. .0..0. .0..0. .1..1. .0..0. .1..0. .0..1. .0..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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