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A251460
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Number of (n+1) X (1+1) 0..2 arrays with every 2 X 2 subblock summing to a prime and those sums nondecreasing in every row and column.
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1
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46, 168, 602, 1908, 5926, 17424, 50306, 141792, 392326, 1077744, 2902034, 7839120, 20718262, 55312368, 144223010, 381727440, 985187686, 2590354800, 6631981106, 17346061392, 44125124758, 114917794032, 290786392514, 754633003728
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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) = 2*a(n-1) + 19*a(n-2) - 38*a(n-3) - 136*a(n-4) + 272*a(n-5) + 456*a(n-6) - 912*a(n-7) - 720*a(n-8) + 1440*a(n-9) + 432*a(n-10) - 864*a(n-11).
Empirical g.f.: 2*x*(23 + 38*x - 304*x^2 - 370*x^3 + 1656*x^4 + 1266*x^5 - 4716*x^6 - 1800*x^7 + 6912*x^8 + 1080*x^9 - 3888*x^10) / ((1 - 2*x)*(1 - 2*x^2)^2*(1 - 3*x^2)*(1 - 6*x^2)^2). - Colin Barker, Nov 29 2018
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EXAMPLE
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Some solutions for n=4:
..0..1....2..0....0..1....0..0....0..2....2..0....2..0....0..2....0..0....1..0
..1..0....2..1....0..2....0..2....0..1....1..0....0..0....1..0....1..2....2..2
..1..0....2..2....0..1....0..0....2..2....2..0....0..2....2..0....0..0....0..1
..1..1....2..1....1..1....0..2....0..1....1..2....0..1....1..0....2..1....2..2
..2..1....2..2....1..2....1..2....2..2....0..2....2..2....0..2....1..1....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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