Quote:
Originally Posted by a1call
I see, thanks for the explanation. 
"PRP Cofactor" title is probably not the best choice of words then. |
It is, because if cofactor (the rest of the number, when divided by known certainly-prime factors) is PRP, then if the number has only one certainly-prime factor, it means it is most probably a semiprime.
If the cofactor is tested composite by PRP test, the cofactor is certainly composite.
If you refer to
this page, then yes, it may be kind of confusing to see PRP cofactor written there, but that's really only a title. If it would be PRP, for real, it would have had written "PRP_PRP_PRP_PRP_" in place of residue.