# Ulam's spiral

![](https://upload.wikimedia.org/wikipedia/commons/3/34/Spirale_Ulam_150.jpg)

A variant of Ulam's spiral

[https://en.wikipedia.org/wiki/Number\_theory](https://en.wikipedia.org/wiki/Number_theory) [https://en.wikipedia.org/wiki/Prime\_number](https://en.wikipedia.org/wiki/Prime_number) [https://en.wikipedia.org/wiki/Ulam\_spiral](https://en.wikipedia.org/wiki/Ulam_spiral)
