There are axiomatic treatments of econ that try to be "mathematical" in a more rigorous sense. Not really sure how much of a cargo cult this is, or more to the point, whether or not it's worth your time to go down this road (not sure if I can emphasize this enough, don't let rigor-mortis hide the elementary utility of the theory be hidden by abstract non-sense), but I've heard good things about Ariel Rubinstein's books, which he has

available for free as PDFs on his site. I've glanced through his micro book, which seems to be geared for grad students, but the prose seems to be good, and it uses precise mathematical language that you might appreciate as a mathematician.

Some other reasons I think he might be a good author:

- There was an Amazon reviewer who was a fan of Ayn Rand and got super pissed that he talked about his socialist views in the epilogue of one of his texts
- He basically thinks that economics is no more than a collection of fables, and is highly skeptical that game theory can possibly be useful, except as allegories--despite the fact that he himself is a game theorist and has published a book on game theory

Disclaimer: I don't even know econ 101, so don't listen to me. But if I had to hold my nose and learn it, this is the route I might take, with the qualification that it's worse to be fooled by fake mathematical rigor than read an econ book that uses "sloppy" math but gets all the important basics right.