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A252427
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Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 4 6 or 7
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1
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915, 688, 914, 1801, 2993, 6164, 13139, 26670, 55677, 119785, 248291, 522400, 1128516, 2346628, 4950707, 10715161, 22309343, 47111547, 102054851, 212611950, 449193290, 973471926, 2028637174, 4287035224, 9292670275, 19367979783
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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) = 16*a(n-3) -74*a(n-6) +146*a(n-9) -294*a(n-12) +336*a(n-15) -316*a(n-18) +290*a(n-21) -119*a(n-24) +11*a(n-27) +6*a(n-30) -a(n-33) for n>37
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EXAMPLE
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Some solutions for n=4
..2..2..3..2....1..0..3..1....2..2..3..2....3..3..1..3....3..2..2..3
..0..2..2..3....2..3..2..2....0..2..2..0....3..2..2..3....0..1..3..3
..3..1..3..0....2..2..0..2....3..1..3..3....2..3..2..2....2..2..3..2
..2..2..3..2....1..3..3..1....2..2..3..2....0..3..1..3....3..2..2..3
..3..2..2..3....0..0..2..2....3..2..2..3....3..2..2..3....3..1..3..0
..0..1..3..0....2..2..3..2....3..1..0..3....2..0..2..2....2..2..3..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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