Pépin's Theorem
The Fermat Number 
is Prime Iff
See also Fermat Number, Pépin's Test, Selfridge-Hurwitz Residue
- Harmonic Map
- Harmonic Mean
- Harmonic Mean Index
- Harmonic Number
- Harmonic Progression
- Harmonic Range
- Harmonic Ratio
- Harmonic Segment
- Harmonic Series
- Harmonic System of Points
- Harmonious Graph
- Harnack's Inequality
- Harnack's Theorems
- Harshad Number
- Hartley Transform
- Hart's Inversor
- Hart's Theorem
- HashLife
- Hasse-Davenport Relation
- Hasse Diagram
- Hasse-Minkowski Theorem
- Hasse Principle
- Hasse's Algorithm
- Hasse's Conjecture
- Hasse's Resolution Modulus Theorem