950976

Appears in sequences

• Harmonic or Ore numbers: numbers k such that the harmonic mean of the divisors of k is an integer.at n=30A001599
• Numbers k whose average divisor is nonintegral and divides k.at n=3A046999
• Sum of divisors of Ramanujan's highly composite numbers, or sigma(A002182(n)).at n=31A063072
• Harmonic numbers (A001599) which are not perfect (A000396).at n=26A090945
• Harmonic numbers that are not multiply-perfect.at n=22A140798
• a(n) = sum of divisors of A094348(n).at n=34A182941
• Numbers k for which sigma(k)/k - 1/9 is an integer.at n=3A218414
• Expansion of (phi(-q^3)^2 / (phi(-q) * phi(-q^9)))^2 in powers of q where phi() is a Ramanujan theta function.at n=35A227587
• 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=20A325022
• Harmonic numbers with a record number of harmonic numbers that can be generated from them using an iterative process of multiplying by primes (see Comments).at n=4A335371
• Numbers whose numerator and denominator of the harmonic mean of their divisors are both 3-smooth numbers.at n=21A348867
• Numbers k such that the continued fraction of the harmonic mean of the divisors of k contains a single distinct element.at n=42A349476
• -a(n)/7! is the coefficient of x^7 in the Taylor expansion of the k-th iteration of sin(x).at n=26A366827