#2 speed improvement

[Anonymous]

use gmpy.next_prime.

example:

def next_good_u(old_u, log_n):

u = 1
while u < old_u:
for _ in xrange(log_n):
#u += 2
#while not isprime(u):
# u += 2
u = long(next_prime(u))
return u

and in mainloop too.

factorization of 2**345+1 took around 50s und now it only takes 23s!!! (on 2GHz, python2.4.4, gmp4.1.2)