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A252186
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Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 1 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 1 3 6 or 7.
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1
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1440, 1886, 2610, 3996, 6368, 9508, 15094, 24092, 36352, 58610, 94310, 142892, 231354, 373418, 566836, 919562, 1486322, 2258180, 3666858, 5930882, 9014692, 14644970, 23695010, 36023012, 58535274, 94723298, 144020836, 234052202
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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) = 7*a(n-3) -14*a(n-6) +8*a(n-9) for n>16.
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EXAMPLE
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Some solutions for n=4
..0..0..0..0....0..1..2..0....1..2..3..1....2..0..1..2....3..3..1..3
..0..2..1..0....3..2..1..0....2..1..0..0....0..0..3..3....1..2..3..2
..3..1..2..3....0..3..3..0....0..3..0..0....1..3..2..1....2..2..3..2
..0..0..3..0....0..1..2..0....1..2..3..1....2..3..1..2....3..3..1..3
..3..2..1..0....0..2..1..0....2..1..0..2....3..0..0..0....2..2..3..1
..0..1..2..3....0..3..0..3....0..3..0..0....1..0..2..1....2..2..3..2
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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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