782481673domain: NAppears in sequencesOdd composite numbers n, not squares of primes, such that (A001065(n) - A032742(n)) divides (n - A032742(n)), where A032742 gives the largest proper divisor, and A001065 is the sum of proper divisors.at n=18A326064Integers k such that sigma(k)/k - 1 is a rational square.at n=27A383482