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A223571
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Number of nX3 0..2 arrays with antidiagonals unimodal
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1
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27, 729, 16038, 352836, 7762392, 170772624, 3756997728, 82653950016, 1818386900352, 40004511807744, 880099259770368, 19362183714948096, 425968041728858112, 9371296918034878464, 206168532196767326208
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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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Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24
a(n) = U(min(n,3))^(max(n,3)-min(n,3)+1) * product{ U(i)^2 , i=1..(min(n,3)-1) }
a(n) = 22*a(n-1) for n>2
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EXAMPLE
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Some solutions for n=3
..1..2..1....1..2..2....0..1..0....0..1..0....0..2..0....2..0..0....2..1..0
..2..1..1....0..2..2....0..1..2....1..1..2....1..0..2....1..1..1....2..0..2
..2..0..0....2..1..0....1..2..1....2..2..1....1..0..0....1..1..0....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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