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A252304
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Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 1 3 6 or 7.
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1
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12027, 7625, 8650, 11639, 22521, 34279, 48579, 109845, 172039, 240515, 630341, 1001223, 1372035, 4084741, 6541831, 8798211, 28880133, 46506247, 61723395, 215907589, 348800263, 459211011, 1666815237, 2697504007, 3535502595
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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) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>24.
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EXAMPLE
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Some solutions for n=4
..0..0..0..0..3..3..0..3..3....3..1..2..0..1..2..3..1..2
..1..3..2..1..0..2..1..0..2....3..0..3..0..0..0..3..0..0
..1..2..0..1..2..0..1..2..3....2..1..3..2..1..0..2..1..0
..0..3..3..0..3..3..0..0..0....0..1..2..3..1..2..3..1..2
..1..0..2..1..0..2..1..3..2....0..0..0..3..0..0..3..0..3
..1..2..0..1..2..3..1..2..0....2..1..0..2..1..0..2..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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