4713984

Appears in sequences

• Harmonic seed numbers.at n=16A035527
• Numbers n for which sigma(n)/n = k+1/3 with integer k.at n=7A160320
• Numbers k that divide 3*sigma(k).at n=26A245774
• Numbers k such that A017666(k) = denominator(sigma(k)/k) = 3.at n=15A245775
• 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=29A325022
• Harmonic numbers m with a record number k of distinct prime numbers p_i (i = 1..k) that do not divide m such that m*p_1, m*p_1*p_2, ... , m*p_1*...*p_k are all harmonic numbers.at n=5A335370
• 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=7A335371
• Numbers whose numerator and denominator of the harmonic mean of their divisors are both 3-smooth numbers.at n=26A348867
• Numbers k such that the continued fraction of the abundancy index of k contains a single distinct element.at n=30A349686
• Abundant numbers k such that k^2 + A033880(k)^2 is a perfect square.at n=18A377134