159530

Appears in sequences

• Integers x such that for some integer y we have uphi(x) = uphi(y) = x-y, where uphi(n) = A047994(n) is the unitary totient function: If n = Product p_i^e_i, uphi(n) = Product (p_i^e_i - 1).at n=18A067739
• a(n) = n * Sum_{d|n} binomial(n,d)/gcd(n,d).at n=17A105862