29719872

Appears in sequences

• Numbers k such that phi(sigma(k)) = k.at n=17A001229
• Numbers n such that uphi(sigma(n)) = n, where the uphi is the unitary phi function A047994.at n=38A030164
• Numbers k such that k = phi(sigma(phi(sigma(k)))).at n=37A067883
• Numbers k such that k = phi(sigma(phi(sigma(phi(sigma(k)))))).at n=32A067884
• Numbers which are the minimum of a cycle in the map x -> phi(sigma(x)).at n=37A376256