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A185461
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Number of (n+1) X 4 binary arrays with no 2 X 2 subblock determinant equal to any horizontal or vertical neighbor 2 X 2 subblock determinant.
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1
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92, 240, 866, 2766, 8762, 27102, 83688, 258056, 795746, 2453840, 7566872, 23333794, 71953944, 221882868, 684215602, 2109901528, 6506259672, 20063218306, 61868531104, 190782709036, 588312691858, 1814167673456, 5594311312512
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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) + 2*a(n-2) + 3*a(n-3) + 2*a(n-4) + 4*a(n-5) + 2*a(n-6) for n>12.
Empirical g.f.: 2*x*(46 + 28*x + 101*x^2 + 139*x^3 + 297*x^4 + 300*x^5 + 393*x^6 + 357*x^7 + 316*x^8 + 194*x^9 + 112*x^10 + 32*x^11) / (1 - 2*x - 2*x^2 - 3*x^3 - 2*x^4 - 4*x^5 - 2*x^6). - Colin Barker, Apr 15 2018
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EXAMPLE
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Some solutions for 3 X 4:
..0..1..1..1....1..0..0..1....1..0..1..0....1..1..1..1....0..0..1..0
..1..1..1..0....1..1..1..1....0..1..0..1....1..0..1..1....1..1..0..1
..0..1..0..0....0..0..1..1....1..1..1..1....1..1..0..1....1..0..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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