(x1^2n)*(x2^2n) is not equal to (x1*x2)^2n
The way I did it was to record a list of the large primes I had found and at what x. When I found it again I added the prime to the factorbase and the two relations to the normal set of relations. When I find it for a third time it just gets added etc.
@Jasonp Do you keep all the large primes in a separate list and eliminate them before doing linear algebra or something? Are you assuming you will only find each large prime twice?
