Earlier quoted context omitted.
Logic more so than mathematics. Mathematics as a means to achieve efficiency, which is an afterthought most of the time. Most working programmers don't need more than a basic understanding of algebra.
Logic is a form a mathematics, and understanding logic is essential. Indeed, for many programmers, that's the extent of the math they know and use. And that's what limits them. There is so much more.
Unless you're solving mathematical problems, how does math directly translate to programming (ignoring efficiency)? I agree with the sentiment that the connection is over-stated. Whenever I hear this argument, it feels like reductive FP propaganda. I'm interested in FP, but not because "it's just math". Sometimes it's nice to piggyback off of mathematics, and it's true that a program is a sort of proof, but sometimes (most of the time) it's better to not be so formal, and not be so academic.
Also, math and logic are obviously related, but logic is not "a form of mathematics". If anything, mathematics is a form of logic.