Trippy brain massages from Sam Palmer's artwork on the front of Issue 16

Tanmay Kulkarni intentionally gets lost on the Tokyo subway

We review the fourth of this year's nominees for the Book of the Year

David Sheard explores the rich mathematics and history behind the Apollonian packing, and the cover of issue 11

A month celebrating the contributions of black mathematicians

Infinitely many primes ending in 1, 3, 7 and 9 proved in typically Eulerian style.