345350598642domain: NAppears in sequences1/4 the number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.at n=5A2095451/4 the number of (n+1)X7 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.at n=5A209551