Why Prime Numbers Form Spirals: Dirichlet's Theorem
3Blue1Brown · Explainer · YouTube title: Why do prime numbers make these spirals? | Dirichlet’s theorem and pi approximations
Why it's here
Frequently recommended as the clearest explanation of prime spirals and the Ulam spiral.
What it covers
3Blue1Brown explains why plotting primes in polar coordinates produces spiral patterns, using modular arithmetic, Dirichlet's theorem and rational approximations of pi.