# Williams primes

## Definition

Williams numbers are natural numbers of the form [math](b{-}1) \cdot b^n{-}1[/math] for integers [math]b\geq2[/math] and [math]n\geq1[/math].

Williams primes are Williams numbers which are prime.

## Available

## External links

- H. C. Williams, The primality of certain integers of the form 2Ar^n-1, Acta Arith. 39 (1981), 7-17.
- Article at en.wikipedia
- Search maintaind by Steven Harvey