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A252155
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Number of (n+2)X(6+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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8309, 8769, 17803, 29825, 57271, 112547, 223442, 447713, 891380, 1776728, 3561844, 7105520, 14181200, 28426208, 56753264, 113330576, 227147536, 453675152, 906181712, 1816146128, 3628012880, 7247618768, 14525051344, 29018570960
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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) +14*a(n-3) -14*a(n-4) -56*a(n-6) +56*a(n-7) +64*a(n-9) -64*a(n-10) for n>15
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EXAMPLE
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Some solutions for n=4
..3..3..2..0..2..0..2..3....3..3..3..3..3..3..3..2....3..3..2..0..2..0..3..1
..3..2..0..2..0..2..0..3....3..0..2..0..2..0..2..0....3..2..0..2..0..2..0..3
..2..0..2..0..2..0..2..3....3..2..0..2..0..2..0..2....3..0..2..0..2..0..2..0
..0..2..0..2..0..2..0..3....2..0..2..0..2..0..2..0....3..2..0..2..0..2..0..2
..2..0..2..0..2..0..2..3....0..2..0..2..0..2..0..3....2..0..2..0..2..0..2..3
..0..2..0..2..0..2..0..2....3..3..3..3..2..0..3..1....0..2..0..2..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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