%I #4 Mar 31 2012 12:36:08

%S 50,8,3790,1476,3607148,296232

%N Number of (n+1)X(n+1) 0..2 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation

%C Column 2 of A187528

%e Some solutions for 4X4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 10 2011