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A252277
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Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 2 3 4 6 or 7
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1
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1260, 7922, 37160, 85808, 518498, 2489352, 5767680, 34496526, 165959340, 384876232, 2298587370, 11061103280, 25655550076, 153191338398, 737201742464, 1709930351560, 10209850851410, 49133026339596, 113963788270572
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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) = 86*a(n-3) -1415*a(n-6) +8680*a(n-9) -22666*a(n-12) +28036*a(n-15) -15888*a(n-18) +3168*a(n-21) for n>27
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EXAMPLE
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Some solutions for n=4
..3..2..3..0..2..3..3..2..3....3..2..3..3..2..0..3..2..0
..2..1..2..2..1..2..2..1..2....2..1..2..2..1..2..2..1..2
..0..2..3..3..2..3..0..2..3....3..2..3..3..2..3..3..2..3
..3..2..3..3..2..3..3..2..0....0..2..3..3..2..0..3..2..0
..2..1..2..2..1..2..2..1..2....2..1..2..2..1..2..2..1..2
..0..2..3..0..2..3..3..2..3....3..2..3..3..2..3..3..2..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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