Too Simple to Solve

A Visual Exploration of the Data of the Collatz Conjecture

A visualisation of 100,000 Collatz sequences for initial values ≤ 1,000,000. Image by author.

There is a maths problem that is so simple even a first-grader can understand it, but so complicated that the world’s greatest mathematicians have warned others away from it.

It starts like this. Pick a number. If it’s even, divide it by 2. If it’s odd, multiply it by 3 and add 1. Repeat with the new…