I think that most jobs that require CS & Maths knowledge will allow you to work flexibly if you find the right company/gig.

I also think that you are looking at this situation the wrong-way round. There is so much more to a job than just being able to work remotely. What you are asking is almost akin to "What kind of job lets me work at a desk?".

There are many, many kinds of jobs out there that could involve maths and CS, you need to be more specific about your skillset and what you enjoy. For example, the career path of an actuary will be very different from that of a computer games programmer.