improved prime number generator to check only up to sqrt(n) instead of n (#1984)
improved prime number generator to check only up to sqrt(n) instead of n (#1984)

* improved prime number generator to check only up to sqrt(n) instead of n

* added old version as slow_primes() and named new, faster version primes()

* fixed docstring in slow_primes

* Add a timeit benchmark

* Update prime_numbers.py

Co-authored-by: Christian Clauss <585dd401264c1e46d17ebec1862e5d2a9b6a6c5d@me.com>
TheAlgorithms/Python