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A235443
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Number of (n+1) X (2+1) 0..1 arrays with the difference between each 2 X 2 subblock maximum and minimum lexicographically nondecreasing rowwise and columnwise.
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1
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58, 382, 2476, 15936, 102376, 657290, 4219322, 27083638, 173846264, 1115891712, 7162725052, 45976338618, 295114433334, 1894290182854, 12159131749324, 78047432228320, 500973408338488, 3215664483364362, 20640812260995146
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 8*a(n-1) - 8*a(n-2) - 16*a(n-3) + 12*a(n-4) + 14*a(n-5) - a(n-6) - 2*a(n-7).
Empirical g.f.: 2*x*(29 - 41*x - 58*x^2 + 56*x^3 + 56*x^4 - 5*x^5 - 8*x^6) / ((1 - x - x^2)^2*(1 - 6*x - 3*x^2 + 2*x^3)). - Colin Barker, Oct 19 2018
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EXAMPLE
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Some solutions for n=4:
..1..1..1....0..0..1....0..1..1....1..1..1....1..0..1....1..1..1....0..1..0
..0..0..1....1..0..1....1..1..0....1..0..0....0..0..0....1..1..1....0..0..1
..1..1..1....0..1..0....1..0..0....0..1..0....0..1..0....1..1..1....1..0..0
..1..0..0....1..0..0....0..1..1....1..1..0....1..0..0....0..0..1....1..1..0
..0..0..1....1..0..1....1..0..0....0..1..0....0..1..1....1..0..1....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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