Project Euler problem zero Created 2025-10-14 Updated 2025-10-27
This was a registration CAPTCHA problem as of 2025:
Among the first 510 thousand square numbers, what is the sum of all the odd squares?
Python solution:
s = 0
for i in range(1, 510001, 2):
    s += i*i
print(s)
At: euler/0.py