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A208439
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Number of n X 2 0..2 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it.
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1
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6, 28, 134, 646, 3118, 15052, 72662, 350776, 1693360, 8174678, 39463082, 190507418, 919671000, 4439696150, 21432553756, 103465280456, 499476814534, 2411215573070, 11640100762206, 56192382129180, 271267737270734
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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) = 3*a(n-1) + 10*a(n-2) - 7*a(n-3) + 8*a(n-4) - 8*a(n-5).
Empirical g.f.: 2*x*(1 - x)*(3 + 8*x + 3*x^2 + 6*x^3) / (1 - 3*x - 10*x^2 + 7*x^3 - 8*x^4 + 8*x^5). - Colin Barker, Jul 03 2018
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EXAMPLE
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Some solutions for n=4:
..2..0....0..2....0..2....0..2....2..0....0..1....0..2....2..0....1..0....2..0
..0..1....2..0....1..0....1..1....0..2....2..1....1..2....1..2....2..2....1..2
..2..1....0..1....0..1....2..0....1..0....0..0....2..0....0..2....0..0....0..2
..0..2....2..1....2..0....0..1....2..2....1..1....0..2....1..0....2..0....2..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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