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A190026
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Number of (n+2) X 4 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock.
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1
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112, 45, 79, 155, 235, 295, 355, 423, 531, 740, 1037, 1434, 1992, 2706, 3628, 4920, 6665, 9015, 12293, 16738, 22710, 30902, 42006, 56987, 77466, 105302, 142987, 194362, 264198, 358864, 487699, 662831, 900478, 1223669, 1662993, 2259498
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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) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-4) +a(n-5) +a(n-6) -a(n-7) for n>10.
Empirical g.f.: x*(112 - 179*x + 101*x^2 - 70*x^3 + 183*x^4 - 121*x^5 - 154*x^6 + 71*x^7 + 26*x^8 + 25*x^9) / ((1 - x)*(1 - x - x^3 + x^4 - x^6)). - Colin Barker, May 03 2018
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EXAMPLE
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Some solutions for 6 X 4:
..0..0..1..1....0..0..0..0....0..0..0..0....1..1..0..1....0..0..0..0
..0..0..0..1....0..0..0..0....0..0..0..0....0..1..1..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....1..0..1..1....0..0..0..0
..0..0..0..0....1..0..0..0....0..0..0..0....1..1..0..1....0..0..0..0
..0..0..0..0....1..1..0..0....1..0..0..0....0..1..1..0....1..0..0..0
..1..1..1..1....1..1..1..0....0..0..0..1....1..0..1..1....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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