28371968domain: NAppears in sequencesNumber of (n+1)X(n+1) 0..7 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum.at n=2A187407Number of 4X4 0..n zero-diagonal arrays with corresponding row and column sums equal.at n=6A229418