def main():
# tris = [n for n in geometry.triangle_numbers(50000)]
pents = [n for n in geometry.pent_numbers(50000)]
hexs = [n for n in geometry.hex_numbers(50000)]
for tri_n in geometry.triangle_numbers():
if utils.list_has(pents, tri_n) and utils.list_has(hexs, tri_n): # fast binary-search
# if tri_n in pents and tri_n in hexs: # old slow approach
if tri_n > 40755:
print tri_n
break
"""
The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...
Let us list the factors of the first seven triangle numbers:
1: 1
3: 1,3
6: 1,2,3,6
10: 1,2,5,10
15: 1,3,5,15
21: 1,3,7,21
28: 1,2,4,7,14,28
We can see that 28 is the first triangle number to have over five divisors.
What is the value of the first triangle number to have over five hundred divisors?
"""
import geometry
import utils
# print divisors(28)
for n in geometry.triangle_numbers():
if utils.n_divisors(n) > 500:
print n
break