4142880

Appears in sequences

• a(n) = A046673(n)/2.at n=4A046674
• Triangle read by rows: T(n,k) = Sum_{i=k..n} i!*Stirling2(n,i), n >= 1, 1 <= k <= n.at n=42A084416
• Triangle read by rows: T(n,k)=sum((n+1-i)!*stirling2(n,n+1-i),i=1..k), n>=1, 1<=k<=n.at n=38A084417
• a(n) = n! * Sum_{k=1..floor(n/2)} 1/(2k).at n=10A092691
• Expansion of e.g.f. -log(1-x)/(1-x^2).at n=10A092692
• Triangle read by rows of partial Bell polynomials B_{n,k} (x_1,...,x_{n-k+1}) evaluated at 2, 2, 12, 72, ..., (n-k)(n-k+1)!, n>=1, 1<=k<=n.at n=40A353131