16709332608domain: NAppears in sequencesComposite numbers n that divide 2 * sigma(n) - d(n) [that is, 2 * sum of divisors - number of divisors].at n=21A135470n such that 3 < sigma(n)/n < sigma(m)/m for all abundant numbers m<n such that 3 < sigma(m)/m.at n=23A259312