## prime number

**Julian Havil**looks at a little-known algorithm that sieves out all primes up to a given number, and which is astonishing in its simplicity.

**Abigail Kirk**investigates a method that does just that.

- Happy birthday Plus! — celebrating 10 years of bringing mathematics to life
- Plus 10 — what were the greatest mathematical advances in the last decade?

The Great Internet Mersenne Prime Search strikes again

**Phil Wilson**, why should this be? Is mathematics a universal truth, and how would we tell?

*Plus*, Marcus du Sautoy continues his exploration of the greatest unsolved problem of mathematics: The

**Riemann Hypothesis**.