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%I #6 Aug 12 2016 06:54:00
%S 6,23,126,943,8360,87289,1073932,14863289,227066403,3688250645,
%T 62544807055,1087937056186,19275800685449,345623392929734,
%U 6258184177158268,114122197400700402,2094043644897109885
%N Number of 4Xn arrays containing n copies of 0..4-1 with no element 1 greater than its west, northeast or northwest neighbor modulo 4 and the upper left element equal to 0.
%C Row 4 of A266994.
%H R. H. Hardin, <a href="/A266996/b266996.txt">Table of n, a(n) for n = 1..19</a>
%e Some solutions for n=6
%e ..0..2..2..1..1..0....0..0..0..3..3..2....0..0..3..3..3..2....0..2..1..3..1..0
%e ..2..2..1..1..0..0....2..0..3..3..1..1....0..2..2..2..1..1....2..0..2..0..2..0
%e ..2..1..0..3..3..3....0..2..2..1..1..1....0..0..2..1..1..3....2..1..3..1..3..2
%e ..0..2..1..3..3..3....2..2..1..0..3..3....2..0..3..1..1..3....3..1..0..3..1..3
%Y Cf. A266994.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 08 2016