This thread may be of interest, though it definitely has some meandering:
In addition to Case Western which has already been mentioned, Brandeis, U. of Rochester, and Rensselaer Polytechnic are medium to smaller colleges that were noted for strong preparation for med school and that I think would have ample depth in mathematics available (as I believe all three offer through a doctorate in math). I don’t know much about it, but RPI does offer an accelerated BS/MD option.