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A208016
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Number of 6 X n 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 1 vertically.
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1
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16, 256, 784, 4489, 15376, 43264, 167281, 609961, 1974025, 6927424, 24750625, 84456100, 291931396, 1024704121, 3549895561, 12285283921, 42796024384, 148698928225, 515713569424, 1792246207504, 6227984421649, 21622397700121
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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) = a(n-1) + 3*a(n-2) + 21*a(n-3) + 9*a(n-4) - 27*a(n-5) - 81*a(n-6) for n>8.
Empirical g.f.: x*(16 + 240*x + 480*x^2 + 2601*x^3 + 3015*x^4 - 3915*x^5 - 15228*x^6 - 8505*x^7) / ((1 + 3*x^2 - 9*x^3)*(1 - x - 6*x^2 - 9*x^3)). - Colin Barker, Jun 26 2018
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EXAMPLE
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Some solutions for n=4:
..1..0..0..1....1..0..0..1....0..0..1..1....0..0..1..1....1..1..1..0
..0..1..1..0....0..0..1..0....0..0..1..0....1..1..1..1....0..1..0..0
..1..0..0..1....1..0..0..1....0..0..1..0....0..0..1..0....0..1..0..0
..0..1..1..0....0..0..1..0....0..0..1..0....1..1..1..1....0..1..0..0
..1..0..0..1....1..0..0..1....0..0..1..0....0..0..1..0....0..1..0..0
..0..0..1..0....0..0..1..0....0..0..1..0....0..1..0..0....0..1..0..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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