617512896

Appears in sequences

• Triangle read by rows: T(n,k) = (3*n - 2*k)!/((n-k)!^3*k!).at n=39A318107
• a(n) is the number of triangular arrays containing the first 3*(n - 1) positive integers arranged with number n on each side and having different set of the sets of the side integers.at n=5A351223