That's an algorithm. It is not "statistical regression", even if that is the method that was used in its creation.
The whole its-just-statistics-shtick is what's getting out of hand. People are just mindlessly repeating the point because it seemed smart when it was first made. Hint: it no longer does, especially if you use it wrong.
2. Add three
3. Square the result
4. Take this result as your final number
There's an algorithm for f(x) = (7x + 3)^2. Similarly, any map from one space to another is an algorithm if it's describable on paper. Every mathematical proof is analogous to an algorithm in important ways. Math is not "equal to" algorithms, in the sense that two different algorithms can describe the same underlying math, but every description of any math essentially has to be an algorithm.
The only parts of math that would not fit would be anything non-constructible, but we know we are limited to exploring and describing only 0% of that world since our descriptions (algorithms) are countably infinite, and there are constructivists who believe non-constructible things don't exist in any meaningful sense. So, yes, most (or all) of the practice of mathematics is algorithms.
Why are we trying to gatekeep this word?
My word for algorithms that aren't closed-form functions, my life's work, is "repetigrams" because they involve repetition in the form of iteration or recursion.
Hence, math consists of things that correspond to implementations of algorithms.