As HA Helfgott suggests, at many schools, it is quite feasible to simply double-major in math and in computer science.

NYU, as you mention, offers a joint major in math and computer science, including courses in Partial Differential Equations, Functions of a Complex Variable, and Abstract Algebra.

There are also programs in "Mathematical and Computational Science," e.g., @Stanford. Georgia Tech, another school which you mention, offers a "thread" in Theory, including courses in Number Theory and Cryptography, Abstract Algebra, Linear Programming, Monte Carlo Methods, Quantum Information and Quantum Computation.

I think you will have more options than you can imagine by just looking at the major requirements. There are many opportunities for "electives" to pursue your interests.

As HA Helfgott suggests, at many schools, it is quite feasible to simply double-major in math and in computer science.

NYU, as you mention, offers a joint major in math and computer science, including courses in Partial Differential Equations, Functions of a Complex Variable, and Abstract Algebra.

There are also programs in "Mathematical and Computational Science," e.g., @Stanford. Georgia Tech, another school which you mention, offers a "thread" in Theory, including courses in Number Theory and Cryptography, Abstract Algebra, Linear Programming, Monte Carlo Methods, Quantum Information and Quantum Computation.

I think you will have more options than you can imagine by just looking at the major requirements. There are many opportunities for "electives" to pursue your interests (as oxeiman suggests).