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A252518
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Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 2 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 2 4 6 or 7
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1
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475, 798, 1783, 2818, 8354, 21510, 39689, 125839, 336794, 629921, 2053845, 5597331, 10478832, 34721174, 95598360, 178987291, 598478883, 1657157188, 3102740091, 10426225275, 28958128577, 54219655326, 182680987768, 508211364604
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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) = 32*a(n-3) -310*a(n-6) +1093*a(n-9) -1724*a(n-12) +1309*a(n-15) -476*a(n-18) +82*a(n-21) -5*a(n-24) for n>29
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EXAMPLE
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Some solutions for n=4
..3..0..2..3..0....3..3..2..3..3....0..3..2..3..0....3..0..2..3..3
..2..2..1..2..2....2..2..1..2..2....2..2..1..2..2....3..3..2..3..3
..0..3..2..3..3....0..3..2..3..3....3..3..2..3..3....2..2..1..2..2
..3..3..2..3..0....3..3..2..3..3....0..3..2..0..3....0..3..2..3..0
..2..2..1..2..2....2..2..1..2..2....2..2..1..2..2....3..3..2..3..3
..3..0..2..3..3....3..3..2..3..0....3..3..2..3..3....2..2..1..2..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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