35741496domain: NAppears in sequences1/4 the number of (n+1)X4 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.at n=6A2095481/4 the number of (n+1)X8 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.at n=2A209552