title: Sieve of Atkin explanation
body: <p>I am doing a project at the moment and I need an efficient method for calculating prime numbers. I have used the <a href="http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes" rel="noreferrer">sieve of Eratosthenes</a> but, I have been searching around and have found that the <a href="http://en.wikipedia.org/wiki/Sieve_of_Atkin" rel="noreferrer">sieve of Atkin</a> is a more efficient method. I have found it difficult to find an explanation (that I have been able to understand!) of this method. How does it work?  Example code (preferably in C or python) would be brilliant.</p>
  
  <p><em>Edit:</em> thanks for your help, the only thing that I still do not understand is what the x and y variables are referring to in the pseudo code. Could someone please shed some light on this for me?</p>