132753domain: NAppears in sequencesa(n) = (n+1)(n+2)(n+3)(9n^2 + 26n + 20)/120.at n=16A110159Number of nX2 nonnegative integer arrays with upper left 0 and lower right n+2-5 and value increasing by 0 or 1 with every step right or down.at n=18A252970