For Computer Science prospective majors, the introductory sequence consisting of CS101, CS102/MA114 (usually taken concurrently) and CS160 should be planned as early as possible.
For more information, please see math majors requirements.
For Mathematics prospective majors, take Calculus as soon as possible! A number of majors require calculus and the Math/CS department strongly recommends that students take Calculus as soon as possible. For possible math majors it is essential to take calculus in the first year as otherwise there is difficulty fitting the highly sequential math requirements into a four-year frame.
For other students, postponing calculus is bad because this course presumes that students have a mastery of geometry, logs, exponents, trigonometry, functions --and we have found that some students who postpone calculus have begun to get rusty in these prerequisites and may even need to take pre-calculus before starting calculus.
Math majors should strongly consider honors calculus (Math 124-125) This course will help them meet math major requirements more efficiently than ordinary calculus.
Don't overlook Math 105 (History of Math) which carries the HP designation.