It isn't, at all. https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes There's quite a cool GIF on the wiki

It isn't, at all. https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes There's quite a cool GIF on the wikipedia page that shows the actual (fixed size) algorithm. I was hoping that this would be an expanding generalisation of that, but it really isn't.