%I #6 Aug 12 2016 06:53:59
%S 2,7,39,265,1802,12239,84614,597601,4289844,31138558,227912351,
%T 1679866698,12457873439,92883320659,695746287346,5232714491851,
%U 39496475643074,299071199295812,2271081847307045,17290623003826450
%N Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its west neighbor modulo 3 and the upper left element equal to 0.
%C Row 3 of A266309.
%H R. H. Hardin, <a href="/A266310/b266310.txt">Table of n, a(n) for n = 1..83</a>
%e Some solutions for n=4
%e ..0..0..0..0....0..2..2..1....0..2..1..1....0..2..1..1....0..2..1..0
%e ..2..1..1..1....1..0..0..2....2..1..0..2....1..0..0..2....0..2..2..2
%e ..2..2..2..1....1..0..2..1....0..0..2..1....0..2..2..1....1..1..1..0
%Y Cf. A266309.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 26 2015