# Problem 193: Squarefree Numbers

![graphic](img193.gif)

A positive integer n is called squarefree, if no square of a prime
divides n, thus 1, 2, 3, 5, 6, 7, 10, 11 are squarefree, but not 4, 8,
9, 12. How many squarefree numbers are there below 250?