Exercise for the reader
More from Chalkdust

On the cover: cellular automata
Discover the meaning of the coloured squares on the cover of issue 13
Top Ten: Maths-themed days out
The definitive chart of the best day trips
Review of The Element in the Room
Reviewing this week's conundrum prize... science-y stuff staring you in the face!
Names for large numbers
Extending the million, billion, trillion system to much, much bigger numbers
Dear Dirichlet, Issue 03
Prof. Dirichlet tackles deaf colleagues and cold badgers.
Breaking out of the prisoner’s dilemma
What happens if you play the prisoners' dilemma against yourself?
