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A252578
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Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7
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1
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1469, 3286, 10885, 25882, 107651, 395500, 959944, 4006901, 14816006, 35925302, 149837853, 555593556, 1346798430, 5611997409, 20856438080, 50548611374, 210462210945, 783856206336, 1899488450222, 7902528627913, 29493363498624
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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) = 78*a(n-3) -1701*a(n-6) +7656*a(n-9) -30460*a(n-12) +70284*a(n-15) -70416*a(n-18) +25968*a(n-21) -1408*a(n-24) for n>31
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EXAMPLE
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Some solutions for n=4
..2..3..2..1..3..2....0..2..0..0..1..0....0..0..2..0..0..1....0..0..2..0..0..2
..0..0..2..0..0..2....0..0..1..0..0..1....3..1..2..3..2..2....3..1..2..3..2..1
..2..0..0..2..0..0....3..2..2..3..2..2....0..2..0..0..1..0....0..2..0..0..2..0
..2..3..2..2..3..2....0..1..0..0..2..0....0..0..1..0..0..2....0..0..2..0..0..2
..0..0..1..0..0..2....0..0..2..0..0..2....3..2..2..3..2..1....0..1..1..3..2..1
..1..0..0..1..0..0....3..2..1..3..1..2....0..1..0..0..2..0....0..2..0..0..2..0
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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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