242060

Appears in sequences

• Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=23A001599
• Numbers whose divisors' harmonic and arithmetic means are both integers.at n=20A007340
• (1+e)-harmonic numbers: harmonic mean of (1+e)-divisors is an integer.at n=23A053783
• Harmonic numbers (A001599) which are not perfect (A000396).at n=19A090945
• a(n) = smallest number m such that m*tau(m)/sigma(m) = n, or 0 if no such m exists.at n=25A091911
• a(n) = 5*a(n-1) - 5*a(n-2) - 3*a(n-3).at n=12A137212
• Harmonic numbers that are not multiply-perfect.at n=15A140798
• Harmonic numbers m from A001599 such that m*(m-tau(m))/sigma(m) is not an integer, where k-tau(k) = the number of nondivisors of k (A049820), tau(k) = the number of divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).at n=15A325022
• Numbers k such that the continued fraction of the harmonic mean of the divisors of k contains a single distinct element.at n=32A349476
• a(n) is the least number k such that A349497(k) = n, or -1 if no such k exists.at n=25A349498