Möbius Periodic Function
A function periodic with period 
such that
for all
is said to be Möbius periodic.- Russian Roulette
- Ryser Formula
- Rényi's Parking Constants
- Rössler Model
- Saalschützian
- Saalschütz's Theorem
- s-Additive Sequence
- Saddle
- Saddle-Node Bifurcation
- Saddle Point (Fixed Point)
- Saddle Point (Function)
- Saddle Point (Game)
- Safarevich Conjecture
- Safe
- Sagitta
- Saint Andrew's Cross
- Saint Anthony's Cross
- Saint Petersburg Paradox
- Sal
- Salamin Formula
- Salem Constants
- Salesman Problem
- Salient Point
- Salinon
- Salmon's Theorem