John Honorary cruncher Send message Joined: 21 Feb 06 Posts: 2875 ID: 2449 Credit: 2,681,934 RAC: 0
i may seem extremely stupid but what is a factor? i have found 115 factors but do not know what they are.
PrimeGrid offers two subprojects that find "factors": GCW Sieve and PSP Sieve.
The factors you are finding remove candidates from being primality tested (LLR): Cullen/Woodall LLR and PSP LLR (not BOINC yet).
The sieves find factors for the possible prime candidates. After a factor is found, that candidate is removed because it is no longer a possible prime.
Here's an example of a recent factor found in the manual GCW Sieve:
13384653648943 | 3382339*2^3382339-1
This means that 13384653648943 is a factor of 3382339*2^3382339-1. Therefore, 3382339*2^3382339-1 is not prime and so does not have to be primality tested (LLR). 3382339*2^3382339-1 will be removed from the possible prime candidates.