219684364642domain: NAppears in sequencesHalf the number of (n+2)X6 binary arrays with each 3X3 subblock having sum 3, 4, 5 or 6.at n=4A187312Half the number of (n+2)X7 binary arrays with each 3X3 subblock having sum 3, 4, 5 or 6.at n=3A187313