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A252113
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Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 3 6 or 7.
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1
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2468, 1180, 2476, 4488, 11760, 17772, 33216, 84864, 142176, 265728, 678912, 1137408, 2125824, 5431296, 9099264, 17006592, 43450368, 72794112, 136052736, 347602944, 582352896, 1088421888, 2780823552, 4658823168, 8707375104
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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-3) for n>8.
Empirical g.f.: 4*x*(617 + 295*x + 619*x^2 - 3814*x^3 + 580*x^4 - 509*x^5 - 672*x^6 - 2304*x^7) / ((1 - 2*x)*(1 + 2*x + 4*x^2)). - Colin Barker, Dec 01 2018
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EXAMPLE
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Some solutions for n=4:
..0..1..1..0..1..1..0..1..1....3..0..3..0..0..2..0..0..2
..2..0..0..2..0..0..3..0..0....2..1..0..1..1..0..1..1..0
..0..1..1..0..1..1..0..1..1....1..1..0..1..1..0..1..1..0
..0..1..1..0..1..1..0..1..1....0..0..2..0..0..2..0..0..2
..3..0..0..2..0..0..2..0..0....1..1..0..1..1..0..1..1..0
..0..1..1..0..1..1..0..2..1....2..1..0..1..1..0..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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