Determine all pairs of positive integers for which there exists a positive integer such that and have an equal number of divisors.
Determine all pairs $(m, n)$ of positive integers for which there exists a positive integer $s$ such that $sm$ and $sn$ have an equal number of divisors.
Školjka 
of positive integers for which there exists a positive integer 
such that 
and 
have an equal number of divisors.