You haven’t mentioned your budget. If your son will be a full-pay student (if you are not looking for financial aid) there will be many very good schools that will welcome him with open arms.
Please note, that public universities are unlikely to give you any significant financial aid. (Most of their FA is for instate students.) So you’re looking at around $50,000-$60,000+ per year at the better known public universities. If this is not something you can afford, you should concentrate on private universities with strong math programs.