51090

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=13A067739
• Numbers k such that Sum_{d divides k} sigma(d)/phi(d) is an integer.at n=28A068991
• Number of multiples of n which have only distinct and nonzero digits in base 10.at n=33A328287
• a(n) = Sum_{d|n} n^tau(d).at n=14A345271
• Number of binary partitions of n into three kinds of parts.at n=21A373309