122125

Appears in sequences

• Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >= 2n.at n=23A210367
• Triangle defined by T(n,k) = Sum_{j>=0} C(j+k, k) * C((j+k)*k, n-k) / 2^(j+k+1), for n>=0, k = 0..n, as read by rows.at n=40A300280
• Array read by downward antidiagonals: A(n,k) = (k+2)*A(n-1,k+1) + Sum_{j=0..k} A(n-1,j) with A(0,k) = 1, n >= 0, k >= 0.at n=34A370380