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A219137
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Unchanging value maps: number of n X 3 binary arrays indicating the locations of corresponding elements unequal to no horizontal, diagonal or antidiagonal neighbor in a random 0..2 n X 3 array.
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1
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4, 18, 78, 331, 1400, 5949, 25277, 107353, 455938, 1936500, 8224877, 34933256, 148370893, 630171269, 2676507659, 11367850562, 48282330086, 205068091043, 870979546682, 3699285278069, 15711863292777, 66732525229601
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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) = 4*a(n-1) + a(n-2) + a(n-3) - 12*a(n-5) - 10*a(n-6) + 2*a(n-7) + 4*a(n-8).
Empirical g.f.: x*(4 + 2*x + 2*x^2 - 3*x^3 - 20*x^4 - 12*x^5 + 6*x^6 + 4*x^7) / (1 - 4*x - x^2 - x^3 + 12*x^5 + 10*x^6 - 2*x^7 - 4*x^8). - Colin Barker, Jul 25 2018
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EXAMPLE
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Some solutions for n=3:
..0..0..0....1..0..0....0..0..0....0..0..0....0..0..1....0..0..0....0..0..1
..1..0..1....1..0..1....0..0..1....0..1..0....0..0..1....0..0..0....1..0..0
..0..0..0....1..1..1....1..0..0....1..1..1....0..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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