140910

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=16A067739
• Numbers n such that the denominator of the 2n-th Bernoulli number is divisible by n but sum_{d|n} sigma(d)/phi(d) is not an integer.at n=33A099008
• Numbers k such that usigma(k) >= 3*k, where usigma(k) = sum of unitary divisors of k (A034448).at n=25A285615
• Primitive terms of A051487.at n=38A346694
• Squarefree 3-abundant numbers: squarefree numbers k such that A000203(k) > 3*k.at n=25A387153