164010

Appears in sequences

• 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=36A099008
• a(n) = 225*n^2 - 15.at n=26A158559
• Numbers k such that Euler phi(Dedekind psi(k)) > k.at n=12A196200
• a(n) = n * A002445(n).at n=35A228838
• Numbers k such that usigma(k) >= 3*k, where usigma(k) = sum of unitary divisors of k (A034448).at n=29A285615
• Squarefree 3-abundant numbers: squarefree numbers k such that A000203(k) > 3*k.at n=29A387153