def largest_prime_factor(n):
# Calculate the largest prime factor of an integer n
limit = int(n ** 0.5 + 1)
for i in range(limit, 1, -1):
if n % i == 0 and is_probable_prime(i):
return i
def compute():
ans, k = 0, 0
while (k+1)**3 - k ** 3 < limit:
ans += is_probable_prime((k+1)**3 - k ** 3)
k += 1
return ans
