def fermat(n):
"""Returns triplets of the form x^n + y^n = z^n.
Warning! Untested with n > 2.
"""
from itertools import count
for x in count(1):
for y in range(1, x+1):
for z in range(1, x**n+y**n + 1):
if x**n + y**n == z**n:
yield x, y, z
Nicked from the earthbound kid.