7421952

Appears in sequences

• Irregular triangle read by rows: T(n,k) = number of 2-packed n X n matrices with exactly k nonzero entries (0 <= k <= n^2).at n=30A230878
• Number of (n+2) X (4+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 3 6 or 7.at n=22A252110