215622

Appears in sequences

• Numbers n such that (phi(n) + sigma(n))/(rad(n))^2 is an integer > 1 (phi=A000010, sigma=A000203, rad=A007947).at n=8A097982
• Numbers k such that (phi(k) + sigma(k))/rad(k)^2 is an integer, that is (phi(k) + sigma(k)) is divisible by every prime factor of k squared.at n=10A121850
• Numbers k such that rad(k)^2 divides sigma(k).at n=16A173615
• a(n) = 6*n^3.at n=33A244726
• a(n) is the conjectured largest number such that both a(n) and a(n) - n are 11-smooth numbers, or 0 if no such number exists. a(n) can be less than n.at n=21A392256