20204829domain: NAppears in sequencesHalf the number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock diagonal sum differing from its antidiagonal sum by more than 3.at n=7A184224Half the number of (n+1)X9 0..3 arrays with every 2X2 subblock diagonal sum differing from its antidiagonal sum by more than 3.at n=1A184230