An array , of Positive Integers is called a dispersion if

- 1. The first column of is a strictly increasing sequence, and there exists a strictly increasing sequence such that
- 2. ,
- 3. The complement of the Set is the Set ,
- 4. for all for and for all for all .

**References**

Kimberling, C. ``Interspersions and Dispersions.'' *Proc. Amer. Math. Soc.* **117**, 313-321, 1993.

© 1996-9

1999-05-24