641024domain: NAppears in sequencesNumber of (n+2) X (4+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.at n=17A252528Numbers k such that k and k+1 are both in A357605.at n=20A357608