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A252411
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Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7
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1
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426, 1224, 3302, 6231, 21819, 63428, 122653, 433272, 1264088, 2446973, 8647751, 25240256, 48858289, 172693010, 504163906, 975786403, 3449387269, 10072591598, 19492346563, 68913269330, 201282072654, 389463616027, 1377074355675
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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) = 41*a(n-3) -427*a(n-6) -92*a(n-9) +4948*a(n-12) -4734*a(n-15) -16460*a(n-18) +22444*a(n-21) +22257*a(n-24) -37919*a(n-27) -8433*a(n-30) +18472*a(n-33) +420*a(n-36) -516*a(n-39) for n>41
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EXAMPLE
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Some solutions for n=4
..3..2..2..3..2..2....3..2..2..0..2..2....3..2..2..3..2..2....3..2..2..3..2..2
..3..1..0..3..1..0....2..3..2..2..3..2....3..1..0..3..1..3....3..1..3..0..1..3
..2..2..3..2..2..3....3..3..1..3..3..1....2..2..3..2..2..0....2..2..3..2..2..0
..3..2..2..3..2..2....3..2..2..0..2..2....3..2..2..3..2..2....3..2..2..3..2..2
..0..1..3..3..1..3....2..3..2..2..3..2....0..1..3..3..1..3....3..1..3..3..1..3
..2..2..0..2..2..3....0..3..1..3..0..1....2..2..0..2..2..0....2..2..0..2..2..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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