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A265233
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Number of 3Xn arrays containing n copies of 0..3-1 with no equal vertical neighbors and new values introduced sequentially from 0.
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2
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1, 7, 56, 495, 4686, 46456, 475392, 4976271, 52977890, 571434402, 6228357312, 68468597544, 758063599632, 8443936740960, 94545206802816, 1063391499647631, 12007844534804202, 136068111377744686, 1546682224461979920
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Conjecture: n^2*a(n) +(-19*n^2+19*n-6)*a(n-1) +96*(n-1)^2*a(n-2) -144*(n-1)*(n-2)*a(n-3)=0. - R. J. Mathar, Dec 08 2015
Conjecture: a(n) ~ 2^(2*n - 1) * 3^(n - 1/2) / (Pi*n). - Vaclav Kotesovec, Mar 08 2023
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EXAMPLE
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Some solutions for n=4
..0..1..0..2....0..1..2..2....0..1..0..0....0..1..1..2....0..1..1..2
..2..0..2..0....2..0..1..0....2..2..2..2....1..2..2..0....2..0..0..0
..1..1..1..2....0..1..2..1....1..1..0..1....0..0..1..2....1..1..2..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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