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A295842
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Number of n X 3 0..1 arrays with each 1 adjacent to 1 or 2 king-move neighboring 1s.
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1
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4, 29, 104, 467, 2197, 9645, 43335, 195508, 876170, 3935424, 17683045, 79404264, 356636392, 1601851743, 7194361447, 32312564136, 145128246079, 651823344848, 2927580000227, 13148849554269, 59056335597781, 265243849656279
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 4*a(n-1) + a(n-2) + 12*a(n-3) - 30*a(n-4) + 3*a(n-5) - 6*a(n-6) + 6*a(n-7) + 5*a(n-8) + 2*a(n-9).
Empirical g.f.: x*(4 + 13*x - 16*x^2 - 26*x^3 - 3*x^4 + 11*x^6 + 7*x^7 + 2*x^8) / (1 - 4*x - x^2 - 12*x^3 + 30*x^4 - 3*x^5 + 6*x^6 - 6*x^7 - 5*x^8 - 2*x^9). - Colin Barker, Feb 22 2019
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EXAMPLE
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Some solutions for n=7:
..0..0..0. .0..1..1. .0..0..1. .1..1..0. .0..1..0. .0..1..0. .1..0..1
..0..0..1. .0..0..0. .1..0..1. .0..0..1. .1..0..0. .0..1..0. .0..1..0
..1..1..0. .0..1..1. .1..0..1. .0..1..0. .1..0..0. .0..0..0. .0..0..0
..0..0..0. .1..0..0. .0..1..0. .0..0..0. .0..1..0. .1..1..0. .0..0..0
..1..1..0. .1..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..1. .0..0..0
..0..0..0. .0..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..0. .1..0..0
..1..1..1. .0..0..1. .0..1..1. .0..1..0. .0..1..0. .0..0..1. .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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