%I #6 Aug 12 2016 06:53:59
%S 1,2,5,12,33,97,278,821,2504,7766,24609,79116,256012,833076,2724322,
%T 8948557,29528100,97848681,325395649,1085321033,3629107776,
%U 12162007737,40841502890,137415398075,463180693482,1563820191273,5287901007259
%N Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, west or northeast neighbor modulo 3 and the upper left element equal to 0.
%C Row 3 of A266291.
%H R. H. Hardin, <a href="/A266292/b266292.txt">Table of n, a(n) for n = 1..109</a>
%e Some solutions for n=6
%e ..0..2..2..1..1..0....0..0..2..1..1..0....0..0..2..2..2..1....0..2..2..1..1..1
%e ..2..2..1..0..0..2....2..2..1..1..0..0....2..2..1..1..1..0....2..1..1..0..0..0
%e ..1..1..0..0..2..1....2..1..1..0..2..2....2..1..1..0..0..0....1..0..0..2..2..2
%Y Cf. A266291.
%K nonn
%O 1,2
%A _R. H. Hardin_, Dec 26 2015
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