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 A223571 Number of nX3 0..2 arrays with antidiagonals unimodal 1

%I

%S 27,729,16038,352836,7762392,170772624,3756997728,82653950016,

%T 1818386900352,40004511807744,880099259770368,19362183714948096,

%U 425968041728858112,9371296918034878464,206168532196767326208

%N Number of nX3 0..2 arrays with antidiagonals unimodal

%C Column 3 of A223576

%H R. H. Hardin, <a href="/A223571/b223571.txt">Table of n, a(n) for n = 1..210</a>

%F Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24

%F a(n) = U(min(n,3))^(max(n,3)-min(n,3)+1) * product{ U(i)^2 , i=1..(min(n,3)-1) }

%F a(n) = 22*a(n-1) for n>2

%e Some solutions for n=3

%e ..1..2..1....1..2..2....0..1..0....0..1..0....0..2..0....2..0..0....2..1..0

%e ..2..1..1....0..2..2....0..1..2....1..1..2....1..0..2....1..1..1....2..0..2

%e ..2..0..0....2..1..0....1..2..1....2..2..1....1..0..0....1..1..0....1..2..2

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 22 2013

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Last modified January 20 00:34 EST 2022. Contains 350467 sequences. (Running on oeis4.)