Introduction

Harold Cooper discusses a pattern he noticed in ‘visual’ derivations of the formulas for 1+2+⋯+n and 1^2+2^2+⋯+n^2, which led him to a similar derivation for 1^3+2^3+⋯+n^3.

This article showcases spinning diagrams which, surprisingly, do not rely on JavaScript or animated image formats, just HTML and CSS. He shared more insights on this approach in April 2023.