The number 33 has surprising depth Smith Chetanachan/Alamy Stock Photo
Add three cubed numbers, and what do you get? It is a question that has puzzled mathematicians for centuries.
In 1825, a mathematician known as S. Ryley proved that any fraction could be represented as the sum of three cubes of fractions. In the 1950s, mathematician Louis Mordell asked whether the same could be done for integers, or whole numbers. In other words, are there integers k, x, y and z such that k = x3 + y3 + z3 for each possible value …
Article amended on 1 April 2019
We clarified the statement of Louis Mordell’s question
