6264576384domain: NAppears in sequencesHalf the number of (n+2)X4 binary arrays with each 3X3 subblock having sum 3, 4, 5 or 6.at n=6A187310Half the number of (n+2)X9 binary arrays with each 3X3 subblock having sum 3, 4, 5 or 6.at n=1A187315