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A253361
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Number of (n+2) X (2+2) 0..1 arrays with every 2 X 2 and 3 X 3 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally and vertically.
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1
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272, 424, 960, 1536, 3136, 5664, 10496, 20000, 36160, 68672, 125760, 234816, 436032, 807360, 1505344, 2787648, 5189184, 9632576, 17894464, 33259840, 61745728, 114769216, 213107776, 395978560, 735485504, 1366348096, 2538108992
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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) = 5*a(n-2) - 8*a(n-4) + 8*a(n-6) + 4*a(n-8).
Empirical g.f.: 8*x*(34 + 53*x - 50*x^2 - 73*x^3 + 64*x^4 + 172*x^5 + 40*x^6 + 72*x^7) / (1 - 5*x^2 + 8*x^4 - 8*x^6 - 4*x^8). - Colin Barker, Dec 11 2018
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EXAMPLE
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Some solutions for n=4:
..0..1..1..1....0..1..0..1....1..1..1..1....1..0..0..1....0..1..0..0
..1..0..1..0....1..0..1..0....1..0..1..1....0..1..0..1....1..0..1..0
..0..1..1..1....0..0..0..1....1..1..0..1....0..0..0..0....0..1..0..0
..1..0..1..0....1..0..1..0....1..1..1..1....0..1..0..1....0..0..1..0
..1..1..1..1....0..0..0..0....0..1..0..1....1..0..0..0....0..1..0..1
..1..0..1..1....1..0..1..0....1..0..1..1....1..1..0..1....0..0..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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