<p>Personally, I think that it might be best to focus on finding schools that have excellent writing programs (as opposed to English programs or departments) and then explore their math programs too. My perception is that math departments are far more likely to be good than are writing programs. So, if you find a good writing program, it is reasonably likely that the college will also have a good math department.</p>
<p>For job prospects you could either double major, or major in math and minor in writing (or vice versa). As MrMom62 pointed out, getting a writing job can be difficult. However, math expertise is highly valued.</p>
<p>My recommendation goes against conventional wisdom that a major and minor should sort of be related; such as majoring in physics and minoring in math. Nothing wrong with doing that, of course, but some people benefit more by having their major and minor be rather different.</p>
<p>One strong recommendation – look into Kenyon College, which has a long reputation for its writing program. Also has a marvelously relaxing campus.</p>