Formulas
- Reciprocals of primes
- Recombination (cosmology)
- Recursion (computer science)
- Recursive tree
- Redshift
- Reduction potential
- Reed–Muller code
- Reed–Solomon error correction
- Reference range
- Ceva's theorem
- Chamfer (geometry)
- Chance-constrained portfolio selection
- Change-making problem
- Chaos computing
- Secant line