My first attempt at making a prime spiral worked, but it worked with 90° angles. Trying to make it look smoother, I now used an angle and a distance, drawing circles at calculated position.
If the number is prime, it gets white. If it is not, the circle will be gray.
# Python 2.7.7 Code # Pygame 1.9.1 (for Python 2.7.7) # Jonathan Frech 18th of July, 2015