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A208081
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Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 0 1 0 vertically.
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1
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25, 625, 7225, 99225, 1288225, 17098225, 224850025, 2968615225, 39126818025, 516077008225, 6804820046025, 89738392111225, 1183352776011025, 15604910211748225, 205780172363700025, 2713612593438576025
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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) = 10*a(n-1) +59*a(n-2) -216*a(n-3) -146*a(n-4) +568*a(n-5) -58*a(n-6) -208*a(n-7) +35*a(n-8) +6*a(n-9) -a(n-10).
Empirical g.f.: 25*x*(1 + 15*x - 20*x^2 - 180*x^3 + 334*x^4 - 26*x^5 - 144*x^6 + 32*x^7 + 5*x^8 - x^9) / ((1 - 16*x + 38*x^2 - 12*x^3 + x^4)*(1 + 6*x - x^2 - 16*x^3 - x^4 + 6*x^5 + x^6)). - Colin Barker, Jan 20 2018
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EXAMPLE
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Some solutions for n=4:
..1..1..0..0....1..1..0..0....0..1..0..1....1..1..1..1....1..1..0..1
..1..1..0..1....0..1..0..1....1..0..1..0....0..1..1..1....1..0..1..0
..1..0..1..1....0..1..1..1....1..0..1..0....1..0..1..1....1..0..1..1
..0..1..1..0....1..0..1..0....1..1..0..1....1..0..1..0....1..1..0..1
..0..1..1..0....1..0..1..1....0..1..1..1....1..1..0..0....1..1..1..1
..1..0..1..1....1..1..1..1....0..1..1..1....0..1..1..1....0..1..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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