def run():
sum = 0
for i in range(10001):
if eu.is_square(i):
continue
cf = eu.sqrt_continued_fraction(i)
if len(cf) % 2 == 0:
sum += 1
return sum
def pell_min_x(d):
'''
for a given d, this find a solution to Pell (x,y) that
minimizes x.
'''
cf = eu.sqrt_continued_fraction(d)
tail_len = len(cf) - 1
x,y = eu.convergent(cf[:1])
if solves_pell(x,y,d):
return (x,y)
while True:
for i in range(len(cf) - 1):
x,y = eu.convergent(cf[:-1 * (tail_len - i)])
if solves_pell(x,y,d):
return (x,y)
cf += cf[-1 * tail_len:]
