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A252273
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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 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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232, 588, 1407, 2513, 7803, 20430, 37160, 121782, 326774, 596036, 2008782, 5462339, 9969419, 34147305, 93561856, 170807342, 590374668, 1624383132, 2965903730, 10301913228, 28409142949, 51875117033, 180660686571, 498797977816
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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>27
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EXAMPLE
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Some solutions for n=4
..2..2..1..2..2....2..1..2..2..1....3..3..2..3..3....3..3..2..0..3
..3..3..2..3..0....3..2..3..3..2....3..0..2..3..3....2..2..1..2..2
..3..0..2..3..3....3..2..3..3..2....2..2..1..2..2....0..3..2..3..3
..2..2..1..2..2....2..1..2..2..1....0..3..2..3..0....3..3..2..3..3
..3..3..2..3..0....3..2..3..3..2....3..3..2..3..3....2..2..1..2..2
..0..3..2..0..3....3..2..3..0..2....2..2..1..2..2....0..3..2..0..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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