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A203872
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Number of (n+1)X3 0..3 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..3 introduced in row major order
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1
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55, 1135, 23815, 500095, 10501975, 220541455, 4631370535, 97258781215, 2042434405495, 42891122515375, 900713572822855, 18914985029279935, 397214685614878615, 8341508397912450895, 175171676356161468775
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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) = 54*21^(n-1) +1
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EXAMPLE
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Some solutions for n=4
..0..0..1....0..0..0....0..0..0....0..1..0....0..1..0....0..0..0....0..0..0
..1..2..1....1..1..1....1..1..1....0..1..2....0..1..0....1..1..2....1..1..1
..1..2..3....0..2..0....2..0..2....2..3..2....2..1..3....3..3..2....2..2..2
..0..2..3....0..1..0....2..1..1....0..1..1....2..0..2....1..1..0....1..3..1
..1..1..0....2..3..2....3..3..2....2..2..2....2..0..1....3..3..2....1..0..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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