613121

Appears in sequences

• Numbers n such that the sum of composites from the smallest prime factor of n to the largest prime factor of n is equal to the sum of squarefree numbers from the smallest prime factor of n to the largest prime factor of n.at n=22A074255
• G.f. A(x) = F(0,x) where F(0,x) = 1/(1 - x*F(1,x)), F(1,x) = 1/(1 - (2*x*F(2,x))^2)^(1/2), F(2,x) = 1/(1 - (3*x*F(3,x))^3)^(1/3), ..., so that F(n-1,x)^n = 1/(1 - (n*x*F(n,x))^n) for n>=0.at n=13A243161
• a(n) = (p_n)^2 * p_{n+1}, where p_n is the n-th prime, A000040(n).at n=22A251720