Skolem-Mahler-Lerch Theorem
If 
is a Recurrence Sequence, then the set of all 
such that 
is the union of a finite(possibly Empty) set and a finite number (possibly zero) of full arithmetical progressions, where a fullarithmetic progression is a set of the form 
with 
References
Myerson, G. and van der Poorten, A. J. ``Some Problems Concerning Recurrence Sequences.'' Amer. Math. Monthly 102, 698-705, 1995.
- Williams p+1 Factorization Method
- Wilson Plug
- Wilson Prime
- Wilson Quotient
- Douady's Rabbit Fractal
- Double Bubble
- Double Bubble Conjecture
- Double Contraction Relation
- Double Cusp
- Double Exponential Distribution
- Double Exponential Integration
- Double Factorial
- Double Folium
- Double-Free Set
- Double Gamma Function
- Double Point
- Double Sixes
- Double Sum
- Doublet Function
- Doubly Even Number
- Doubly Magic Square
- Dougall-Ramanujan Identity
- Dougall's Theorem
- Doughnut
- Douglas-Neumann Theorem