Coxeter Matrix
An 
Square Matrix 
with
 |  |  | |
 | |  |
for all
, ..., 
.See also Coxeter Group- Hexakis Icosahedron
- Hexakis Octahedron
- Hex Game
- Hexlet
- HexLife
- Hex Number
- Hexomino
- Hex (Polyhex)
- Hex Pyramidal Number
- Heyting Algebra
- H-Fractal
- H-Function
- Hh Function
- Higher Arithmetic
- Highest Weight Theorem
- HighLife
- Highly Abundant Number
- Highly Composite Number
- Higman-Sims Group
- Hilbert Basis Theorem
- Hilbert Curve
- Hilbert Function
- Hilbert Hotel
- Hilbert Matrix
- Hilbert Number