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A218997
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Unmatched value maps: number of n X 3 binary arrays indicating the locations of corresponding elements not equal to any horizontal, diagonal or antidiagonal neighbor in a random 0..2 n X 3 array.
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1
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4, 46, 328, 2374, 17776, 131548, 973492, 7213582, 53429692, 395740366, 2931304708, 21712231084, 160822807612, 1191219388318, 8823392421952, 65355090312238, 484086844724824, 3585643697043796, 26558954938197124, 196722861904335358
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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) + 15*a(n-2) + 66*a(n-3) + 63*a(n-4) + 72*a(n-5).
Empirical g.f.: 2*x*(2 + 15*x + 42*x^2 + 54*x^3 + 36*x^4) / (1 - 4*x - 15*x^2 - 66*x^3 - 63*x^4 - 72*x^5). - Colin Barker, Jul 24 2018
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EXAMPLE
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Some solutions for n=3:
..0..1..0....1..1..1....0..1..0....1..0..0....0..0..0....0..1..1....0..0..0
..0..0..1....0..1..0....0..0..0....0..0..1....0..1..1....1..0..0....1..0..1
..1..0..0....1..0..1....0..1..0....1..0..1....1..0..0....0..1..0....0..1..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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