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A275141
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Number of n X 7 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2.
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1
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32, 1296, 2816, 17872, 107472, 663904, 4055152, 24875600, 152379136, 933805200, 5721947536, 35062147296, 214849132208, 1316520434704, 8067189289984, 49432958970960, 302908230284368, 1856117667993184, 11373652262370288
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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) = 3*a(n-1) + 18*a(n-2) + 11*a(n-3) - 23*a(n-4) - 4*a(n-5) for n>7.
Empirical g.f.: 16*x*(2 + 75*x - 103*x^2 - 891*x^3 - 647*x^4 + 1172*x^5 + 144*x^6) / (1 - 3*x - 18*x^2 - 11*x^3 + 23*x^4 + 4*x^5). - Colin Barker, Jan 31 2019
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EXAMPLE
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Some solutions for n=5:
..0..1..0..2..1..2..0. .0..1..2..0..1..2..0. .0..1..0..2..0..1..0
..0..2..1..0..2..1..2. .2..0..1..2..0..1..0. .0..2..1..0..1..0..1
..1..2..1..0..2..1..0. .2..0..1..2..0..1..2. .1..0..1..0..2..1..2
..1..0..2..1..2..1..0. .1..0..1..2..0..1..2. .2..0..2..1..2..1..0
..2..1..2..1..0..2..1. .0..1..0..1..0..1..2. .0..1..0..2..0..2..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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