data/problems/193.yml
---
:id: 193
:name: Squarefree Numbers
:url: https://projecteuler.net/problem=193
:content: |+
A positive integer <var>n</var> is called squarefree, if no square of a prime divides <var>n</var>, thus 1, 2, 3, 5, 6, 7, 10, 11 are squarefree, but not 4, 8, 9, 12.
How many squarefree numbers are there below 2<sup>50</sup>?