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A252227
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Number of (n+2) X (7+2) 0..2 arrays with every 3 X 3 subblock row and column sum 2 3 or 4 and every diagonal and antidiagonal sum not 2 3 or 4.
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1
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9922, 219824, 718514, 1619714, 4297634, 13842872, 44099648, 135348914, 414030384, 1274652450, 3930132146, 12105939362, 37274285880, 114781892768, 353490924114, 1088626770704, 3352521852434, 10324377012002, 31794906089378
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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) = 3*a(n-1) - a(n-2) + 3*a(n-3) + 3*a(n-4) - a(n-5) - a(n-6) for n>8.
Empirical g.f.: 2*x*(4961 + 95029*x + 34482*x^2 - 172885*x^3 - 266116*x^4 - 117704*x^5 + 41864*x^6 + 39568*x^7) / ((1 - x + 2*x^2 - x^3)*(1 - 2*x - 3*x^2 - x^3)). - Colin Barker, Dec 02 2018
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EXAMPLE
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Some solutions for n=1:
..1..0..2..0..1..1..2..0..1....1..0..2..0..2..0..1..1..1
..0..2..0..2..0..2..0..2..2....0..2..0..2..0..2..0..2..1
..2..0..2..0..1..1..2..0..1....1..1..2..0..2..0..2..0..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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