%I #6 Mar 31 2012 12:37:11
%S 192,181,1340,1581,12021,14181,108141,127581,973221,1148181,8758941,
%T 10333581,78830421,93002181,709473741,837019581,6385263621,7533176181,
%U 57467372541,67798585581,517206352821,610187270181,4654857175341
%N Number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor
%C Diagonal of A206343
%H R. H. Hardin, <a href="/A206335/b206335.txt">Table of n, a(n) for n = 1..34</a>
%e Some solutions for n=4
%e ..1..0..2..0..2....0..1..0..1..0....1..2..0..2..0....3..3..0..1..0
%e ..0..1..0..2..0....1..0..1..0..1....2..0..2..0..2....1..0..3..0..1
%e ..1..0..1..0..2....0..1..0..1..0....0..2..0..2..0....0..1..0..3..0
%e ..0..1..0..1..0....3..0..1..0..1....1..0..2..0..2....1..0..1..0..3
%e ..1..0..1..0..1....0..3..0..1..3....0..1..0..2..0....0..1..0..1..3
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 06 2012