%I #5 Mar 31 2012 12:36:05

%S 20079,14492,82632,101305,433513,418177,1849873,1894849,7687009,

%T 8602033,31645329,39574001,131802797,181420169,553069145,820669641,

%U 2331052105,3678141757,9868524241,16371829777,41936161201,72480530737,178779125389

%N Number of (n+1)X8 0..3 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors

%C Column 7 of A186482

%H R. H. Hardin, <a href="/A186480/b186480.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=2*a(n-1)+2*a(n-2)-6*a(n-3)+6*a(n-4)-3*a(n-5) for n>18

%e Some solutions for 3X8

%e ..0..0..0..0..1..0..0..0....2..0..1..0..1..0..2..0....1..0..2..0..0..0..3..3

%e ..3..0..0..0..0..1..0..0....0..2..0..1..0..1..0..2....0..1..0..2..0..0..0..3

%e ..2..3..0..0..0..0..1..0....3..0..2..0..1..0..1..0....3..0..1..0..2..0..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 22 2011