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A237456
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Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the lower median of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one.
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1
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81, 308, 1144, 4272, 16280, 61152, 231680, 869120, 3299584, 12382208, 46966784, 176229376, 668720640, 2509305856, 9520095232, 35722403840, 135538946048, 508589948928, 1929634152448, 7240635777024, 27472062906368, 103084621299712
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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) = 136*a(n-4) + 832*a(n-6) + 1600*a(n-8) + 1024*a(n-10).
Empirical g.f.: x*(81 + 308*x + 1144*x^2 + 4272*x^3 + 5264*x^4 + 19264*x^5 + 8704*x^6 + 31872*x^7 + 4096*x^8 + 18432*x^9) / (1 - 136*x^4 - 832*x^6 - 1600*x^8 - 1024*x^10). - Colin Barker, Oct 22 2018
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EXAMPLE
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Some solutions for n=5:
..1..0....1..0....1..1....2..2....2..1....2..0....1..1....0..0....2..1....2..1
..0..0....1..0....1..0....1..1....2..0....1..1....1..0....1..2....0..0....2..0
..2..1....0..2....2..2....1..0....2..0....1..0....1..0....1..1....0..1....2..2
..0..2....1..1....2..1....0..0....1..2....0..0....0..2....0..1....1..1....1..1
..1..0....0..1....1..1....2..1....0..0....1..2....2..1....1..0....0..2....1..1
..0..0....0..0....0..1....1..2....1..0....1..1....2..2....0..2....0..0....1..2
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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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