I agree with everything Emile and AngryParsley said. I program for work and for play, and use Python when I can get away with it. You can be shocked, that like AngryParsley, I will recommend my favorite language!

I have an additional recommendation though: to learn to program, you need to have questions to answer. My favorite source for fun programming problems is ProjectEuler. It's very math-heavy, and it sounds like you might like learning the math as much as learning the programming. Additionally, every problem, once solved, has a forum thread opened where many people post their solutions in many languages. Seeing better solutions to a problem you just solved on your own is a great way to rapidly advance.