###################################################################### # 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? ###################################################################### triangleNumber = 1 index = 2 divisors = 0 while divisors <= 500: divisors = 0 triangleNumber += index index += 1 for i in range(1, int(pow(triangleNumber, 0.5) + 1)): if triangleNumber % i == 0: divisors += 2 print(triangleNumber) # Solution: 76576500