304480

Appears in sequences

• Number of 2 X 2 nonsingular 0..n matrices with rows in increasing order.at n=26A183761
• T(n, k) = [x^k] M(n)*Sum_{k=0..n} E2(n, k)*binomial(-x + n - k, 2*n), where E2 are the second-order Eulerian numbers A340556 and M(n) are the Minkowski numbers A053657. Triangle read by rows, T(n, k) for n >= 0 and 0 <= k <= 2*n+1.at n=27A341111