47417927307domain: NAppears in sequences1/4 the number of (n+1)X4 0..3 arrays with every 2X2 subblock having one or four distinct clockwise edge differences.at n=5A2098531/4 the number of (n+1)X7 0..3 arrays with every 2X2 subblock having one or four distinct clockwise edge differences.at n=2A209856