Numbers m that can be written as x*y with phi(x)*sigma(y) = 2*x*y, where x and y are positive integers, phi(.) is Euler's totient function and sigma(y) is the sum of all positive divisors of y.

A279915

Numbers m that can be written as x*y with phi(x)*sigma(y) = 2*x*y, where x and y are positive integers, phi(.) is Euler's totient function and sigma(y) is the sum of all positive divisors of y.