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A208383
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Number of 7 X n 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 1 vertically.
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1
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14, 196, 216, 1200, 4416, 14976, 60984, 231744, 851400, 3276624, 12438144, 46737936, 177585096, 673147200, 2544020136, 9639951936, 36515578944, 138204393264, 523395873000, 1982108510304, 7504603109784, 28417632893376
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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) + 4*a(n-2) + 21*a(n-3) + 14*a(n-4) - 5*a(n-5) + 25*a(n-6) for n>8.
Empirical g.f.: 2*x*(7 + 91*x - 18*x^2 - 47*x^3 - 980*x^4 - 725*x^5 + 375*x^6 - 1250*x^7) / (1 - x - 4*x^2 - 21*x^3 - 14*x^4 + 5*x^5 - 25*x^6). - Colin Barker, Jul 02 2018
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EXAMPLE
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Some solutions for n=4:
..1..1..0..1....0..0..1..0....0..1..1..0....1..1..0..1....1..0..1..0
..1..1..0..0....0..0..1..1....1..0..0..1....0..1..0..1....1..0..0..1
..1..1..0..0....0..0..1..0....1..0..0..1....0..1..0..0....1..0..0..1
..1..1..0..0....0..0..1..0....1..0..0..1....0..1..0..0....1..0..0..1
..1..1..0..0....0..0..1..0....1..0..0..1....0..1..0..0....1..0..0..1
..1..1..0..0....0..0..1..0....1..0..0..1....0..1..0..0....1..0..0..1
..1..1..0..0....0..0..1..0....1..0..0..1....0..1..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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