105664

Appears in sequences

• Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=18A001599
• High temperature series for susceptibility for spherical model on b.c.c. lattice.at n=6A003494
• Numbers whose divisors' harmonic and arithmetic means are both integers.at n=15A007340
• Numbers n such that harmonic mean of the divisors of n is a prime.at n=7A074247
• Duplicate of A007340.at n=15A090944
• Harmonic numbers (A001599) which are not perfect (A000396).at n=14A090945
• a(n) = smallest number m such that m*tau(m)/sigma(m) = n, or 0 if no such m exists.at n=12A091911
• Harmonic numbers that are not multiply-perfect.at n=10A140798
• Corresponding values of arithmetic means of divisors of numbers from A007340.at n=36A157848
• Numbers n such that sigma(n)/tau(n) is a perfect number.at n=18A219179
• 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=10A325022
• Harmonic numbers k such that k*p is not a harmonic number for all the primes p that do not divide k.at n=7A335369
• Numbers whose numerator and denominator of the harmonic mean of their divisors are both Fibonacci numbers.at n=23A348658
• Numbers k such that the continued fraction of the harmonic mean of the divisors of k contains a single distinct element.at n=27A349476