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A223571 Number of nX3 0..2 arrays with antidiagonals unimodal 1
27, 729, 16038, 352836, 7762392, 170772624, 3756997728, 82653950016, 1818386900352, 40004511807744, 880099259770368, 19362183714948096, 425968041728858112, 9371296918034878464, 206168532196767326208 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A223576
LINKS
FORMULA
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
EXAMPLE
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
CROSSREFS
Sequence in context: A223976 A167726 A268022 * A228973 A171301 A098838
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 22 2013
STATUS
approved

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Last modified April 15 11:55 EDT 2024. Contains 371681 sequences. (Running on oeis4.)