# Sierpiński-Riesel Base 5

The **Sierpiński-Riesel Base 5 Project** is a distributed computing project. It was formally managed by users of mersenneforum.org, and is currently a subproject on PrimeGrid.

## Goal

Sierpiński-Riesel Base 5 tries to prove that k=159986 is the smallest possible Sierpiński number base 5 and that k=346802 is the smallest possible Riesel number base 5. To prove this, one must find primes for all k below the smallest known number.

## How to participate

Participants in either of the projects reserve a *k* in the forum, then use NewPGen to sieve and then LLR to PRP test (for primality). After that, users unreserve their *k* again if no primes are found. Instructions to the project can be found at OmbooHankvalds guidepages.

## Status

As of this moment (2019-04-23), there are 32 Sierpiński and 69 Riesel base 5 candidate k left, which need primes.

## Results

Primes from the project can be seen on the status-page of either the Sierpińskis or the Riesels.