12770802domain: NAppears in sequencesNumber of (n+1)X(4+1) 0..1 arrays with every 2X2 subblock having one or two 1s.at n=5A251322Number of (n+1) X (6+1) 0..1 arrays with every 2 X 2 subblock having one or two 1's.at n=3A251324