GCD Sum
April 22, 2016
Today’s exercise is inspired by A018804: Find the sum of the greatest common divisors gcd(k, n) for 1 ≤ k ≤ n.
Your task is to write a function that finds the sum of the greatest common divisors. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.
Programming Praxis 