327856domain: NAppears in sequencesa(n) = n*(n + 1)*(2*n^2 + 2*n - 1)/6.at n=30A006324Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7.at n=14A252307