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A252152
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Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7
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1
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2591, 1898, 3197, 4988, 9572, 17803, 35924, 68613, 140294, 268864, 553258, 1064524, 2194400, 4229940, 8737784, 16851232, 34844104, 67252048, 139112864, 268589808, 555851264, 1073324704, 2221749568, 4290919264, 8882898080, 17157089760
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = a(n-1) +4*a(n-2) +2*a(n-3) -6*a(n-4) -24*a(n-5) +16*a(n-6) +8*a(n-7) +32*a(n-8) -32*a(n-9) for n>14
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EXAMPLE
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Some solutions for n=4
..3..3..2..3..3....2..1..2..2..1....2..0..2..3..3....3..2..3..3..3
..3..2..0..2..3....1..3..1..1..0....0..2..0..2..3....3..0..2..0..3
..3..0..2..0..3....1..0..1..1..3....2..0..2..0..3....3..2..0..2..3
..3..2..0..2..3....2..1..2..2..1....0..2..0..2..3....2..0..2..0..2
..3..0..2..0..2....1..3..1..1..0....2..0..2..0..2....3..2..0..2..3
..3..2..0..2..0....1..0..1..1..3....0..2..0..2..3....3..0..2..3..3
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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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