2025 and Nicomachus’ Theorem: Why the Sum of Cubes Is a Perfect Square

A Remarkable Property of 2025 and the Nicomachus Theorem

By the way, 2025 is one of those numbers! It can be expressed as a sum of cubes — or equivalently, as the square of the sum of consecutive natural numbers from 1 to 9.

Watch the Proof of Nicomachus’ Theorem

A proof of what is now known as Nicomachus’ theorem is available here: https://youtu.be/ZWLkIW4NsQ0?si=BZtrmmOcJOuLv_B6