24-Cell
A finite regular 4-D Polytope with Schläfli Symbol 
. Coxeter (1969) givesa list of the Vertex positions. The Even coefficients of the 
lattice are 1, 24, 24,96, ... (Sloane's A004011), and the 24 shortest vectors in this lattice form the 24-cell (Coxeter 1973, Conway and Sloane1993, Sloane and Plouffe 1995).
References
Conway, J. H. and Sloane, N. J. A. Sphere-Packings, Lattices and Groups, 2nd ed. New York: Springer-Verlag, 1993. Coxeter, H. S. M. Introduction to Geometry, 2nd ed. New York: Wiley, p. 404, 1969. Coxeter, H. S. M. Regular Polytopes, 3rd ed. New York: Dover, 1973. Sloane, N. J. A. SequenceA004011/M5140in ``An On-Line Version of the Encyclopedia of Integer Sequences.''http://www.research.att.com/~njas/sequences/eisonline.html and extended entry inSloane, N. J. A. and Plouffe, S.The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.
- d'Alembert Ratio Test
- d'Alembert's Equation
- d'Alembert's Solution
- d'Alembert's Theorem
- Damped Exponential Cosine Integral
- d-Analog
- Dandelin Spheres
- Danielson-Lanczos Lemma
- Darboux Integral
- Darboux-Stieltjes Integral
- Darboux Vector
- Darling's Products
- Dart
- Darwin-de Sitter Spheroid
- Darwin's Expansions
- Database
- Data Structure
- Daubechies Wavelet Filter
- Davenport-Schinzel Sequence
- Dawson's Integral
- Day of Week
- de Bruijn Constant
- de Bruijn Diagram
- de Bruijn Graph
- de Bruijn-Newman Constant