Erik Darling shows the Collatz Conjecture in T-SQL:

The only problem in there that could really be written in SQL was the Collatz Conjecture. It states that when you take any number, and if it’s even you divide it by 2, and if it’s odd you multiply it by 3 and add 1, you’ll always eventually end up with 1. Fair enough. There’s probably a use for that out somewhere out there.

Writing it in SQL was super easy, of course. Just throw a CASE expression at it.

I think Erik is a little harsh on SQL as a mathematical language. Yeah, there are other languages I’d go to first for many types of math problems (R, F#, and Python being examples), but SQL can solve quite a few mathematical problems.