The code is not even equivalent to the mathematical notation. The code is writtin in a sequential "von Neumann" paradigm. But the mathematical notation does not require any order, or indeed even sequentiality, on the summation.

The code is an implementation. The mathematical notation is the intention. They are different.

A lot can be inferred from the mathematical notation. Are the operations associative? Are they part of a group?

The code tells you nothing.