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A267789
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Number of 3Xn 0..1 arrays with every repeated value in every row greater than or equal to, and in every column greater than, the previous repeated value.
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1
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6, 36, 216, 1056, 5004, 22110, 94554, 391314, 1582824, 6278400, 24520080, 94523100, 360449622, 1361930880, 5105718624, 19011717024, 70378031196, 259193957658, 950281765146, 3470120581542, 12626754295920, 45799000309176
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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) = 8*a(n-1) -12*a(n-2) -40*a(n-3) +80*a(n-4) +100*a(n-5) -134*a(n-6) -160*a(n-7) +8*a(n-8) +48*a(n-9) +8*a(n-10) -4*a(n-11) -a(n-12)
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EXAMPLE
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Some solutions for n=4
..0..0..1..0....0..1..0..1....0..0..1..1....0..1..0..1....1..1..0..1
..0..1..1..1....1..0..1..1....1..1..1..1....1..0..1..0....1..0..1..1
..1..0..0..0....1..0..1..0....1..0..0..0....0..0..0..1....0..1..1..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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