Helper Functions used in Solution to Project Euler Problem 12

euler12functions.py

from math import *

# Function to calculate the number of divisors of integer n
def divisors(n):
    limit = int(sqrt(n))
    divisors_list = []
    for i in range(1, limit+1, 1):
        if n % i == 0:
            divisors_list.append(i)
            if i != n/i:
                divisors_list.append(n/i)
    return len(divisors_list)
                
# Function to check for triangle number
def isTriangleNumber(n):
    a = int(sqrt(2*n))
    return 0.5*a*(a+1) == n

# Function to calculate the last term of the series adding up to the triangle number    
def lastTerm(n):
    if isTriangleNumber(n):
        return int(sqrt(2*n))
    else:
        return None