190633

Properties

Appears in sequences

• a(0) = 0; thereafter, a(n) = (2*n-1)*a(n-1) + 1.at n=7A286286
• a(n) = numerator of Sum_{k=1..n} 1/(2*k-1)!!.at n=6A289381
• Triangle T(n,k) read by rows with T(n,0) = (2*n)! / (2^n * n!) for n >= 0 and T(n,k) = (Sum_{i=k..n} binomial(i-1,k-1) * 2^i * i! / (2*i)!) * (2*n)! / (2^n * n!) for 0 < k <= n.at n=29A350557
• Prime numbersat n=17214