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%I #7 Dec 13 2015 18:43:40
%S 2046027,38594841,1770039198,108688211619,7050554283159,
%T 464729380449429,30831727837091925,2051665393581595494,
%U 136747710613864831857,9121868183571809071275,608769411415765774933107
%N Number of (n+1) X 8 0..2 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors.
%C Column 7 of A206668.
%H R. H. Hardin, <a href="/A206667/b206667.txt">Table of n, a(n) for n = 1..21</a>
%e Some solutions for n=4:
%e ..1..1..2..2..1..2..2..1....1..1..0..0..1..2..0..1....0..1..2..1..1..1..1..1
%e ..1..2..2..1..1..2..1..1....0..1..0..1..1..2..0..1....2..2..2..2..2..2..2..0
%e ..1..2..1..1..2..2..1..2....0..1..0..1..2..2..0..0....2..0..0..0..0..0..1..2
%e ..2..2..2..1..1..1..1..1....0..0..0..1..1..2..0..1....2..0..1..1..1..2..0..0
%e ..2..1..1..1..2..2..1..0....2..2..0..0..1..2..0..0....2..0..1..2..0..1..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 11 2012