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A252380
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Number of (n+2) X (4+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.
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1
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1966, 771, 663, 744, 916, 1097, 1361, 1791, 2270, 2976, 4082, 5341, 7204, 10080, 13381, 18273, 25783, 34430, 47252, 66894, 89537, 123120, 174524, 233809, 321745, 456303, 611518, 841752, 1194010, 1600373, 2203148, 3125352, 4189229, 5767329
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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) = 4*a(n-3) - 4*a(n-6) + a(n-9) for n>12.
Empirical g.f.: x*(1966 + 771*x + 663*x^2 - 7120*x^3 - 2168*x^4 - 1555*x^5 + 6249*x^6 + 1211*x^7 + 534*x^8 - 1458*x^9 - 189*x^10 - 14*x^11) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018
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EXAMPLE
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Some solutions for n=4:
..2..1..0..2..1..0....2..0..1..2..3..1....2..3..1..2..0..1....2..3..1..2..0..1
..0..1..2..3..1..2....3..0..0..0..3..0....2..1..0..2..1..3....2..1..0..2..1..3
..0..0..0..3..0..0....3..2..1..0..2..1....0..0..0..0..3..0....0..0..0..0..3..0
..2..1..0..2..1..0....2..0..1..2..3..1....2..0..1..2..0..1....2..0..1..2..0..1
..0..1..2..3..1..1....3..0..0..0..3..0....2..1..3..2..1..0....2..1..3..2..1..3
..0..0..0..3..0..3....3..2..1..0..2..1....0..3..0..0..0..0....0..3..0..0..3..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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