def p21():
limit = 10000
answer = []
for n in xrange(1,limit):
A = sum(lc.divisors(n))
B = sum(lc.divisors(A))
if n == B and n <> A:
answer.append(n)
print sum(answer)
def p12():
start = 1
pivot = 2
stop = 3
chunk = 10
goal = 25
found = False
while not found:
if len(lc.divisors(stop)) < goal:
start = stop + 1
stop *= 2
pivot = (stop-start) // 2
