# cannonball problem

> English word · Proper noun

## Definitions
1. The challenge of proving that the only solution of the Diophantine equation :∑ₙ₌₁ᴺn²=M²; with N > 1 is when N = 24 and M = 70.

## Etymology
It can be visualized as the problem of taking a square arrangement of cannonballs on the ground and building a square pyramid out of them.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/cannonball-problem