That intimidating Σ (capital sigma) notation that made you question your life choices in calculus? Yeah, it's literally just a for-loop. And that Π (capital pi) symbol that looked like a gateway to mathematical hell? Also a for-loop, but with multiplication instead of addition. The summation iterates from n=0 to 4, adding 3*n each time, while the product does the same from n=1 to 4, multiplying by 2*n. Once you realize mathematical notation is just fancy syntax for basic programming constructs, suddenly those textbooks become a lot less threatening. It's the same energy as discovering that "algorithm" is just a pretentious way of saying "recipe."