%I #5 Mar 31 2012 12:37:11
%S 1376,686,4007,2034,12021,6090,36015,18222,107997,54618,323943,163806,
%T 971799,491406,2915385,1474206,8746143,4422606,26238417,13267806,
%U 78715239,39803406,236145705,119410206,708437103,358230606,2125311297
%N Number of (n+1)X6 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor
%C Column 5 of A206343
%H R. H. Hardin, <a href="/A206340/b206340.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) +3*a(n-2) -3*a(n-3) for n>14
%e Some solutions for n=4
%e ..0..1..0..2..0..2....1..2..1..2..1..2....1..1..0..2..0..1....1..0..1..0..2..0
%e ..1..0..1..0..2..0....2..1..2..1..2..1....2..0..1..0..2..0....0..1..0..1..0..2
%e ..0..1..0..1..0..2....1..2..1..2..1..2....0..2..0..1..0..2....1..0..1..0..1..0
%e ..3..0..1..0..1..0....2..1..2..1..2..1....2..0..2..0..1..0....0..1..0..1..0..1
%e ..0..3..0..1..0..1....1..2..1..2..1..2....0..2..0..2..0..1....3..0..1..0..1..2
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 06 2012
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