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A252303
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Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7
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1
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7138, 5056, 6103, 8130, 15444, 24076, 33862, 71636, 117612, 167798, 385332, 662964, 951766, 2359892, 4219348, 6078806, 16019028, 29452116, 42525526, 116755796, 218457940, 315839318, 888530772, 1679113044, 2429346646, 6926306132
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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) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>21
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EXAMPLE
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Some solutions for n=4
..2..1..3..2..2..3..2..2....3..0..0..3..0..0..0..0....2..0..1..2..0..1..2..3
..3..2..2..3..2..2..3..2....0..2..1..3..2..1..3..2....3..3..0..3..0..0..0..3
..3..1..3..3..1..3..3..0....2..0..1..2..3..1..2..3....0..2..1..3..2..1..0..2
..2..2..3..2..2..3..2..2....3..0..0..0..0..0..0..0....2..0..1..2..3..1..2..0
..3..2..2..3..2..2..3..2....3..2..1..3..2..1..3..2....3..0..0..0..3..0..3..0
..3..1..3..3..1..3..3..1....3..3..1..2..3..1..2..3....3..2..1..0..2..1..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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