Square Pyramidal Numbers
March 14, 2017
Cannonballs are traditionally stacked in a pyramid with a square base. A stack with a square base of 15 cannonballs has 15 × 15 = 225 on the bottom level, 14 × 14 = 196 on the level above that, and so on, a total of 1240 cannonballs.
Your task is to write a program to compute the number of cannonballs in a stack; use it to compute the number of cannonballs in a stack with a base of 1,000,000 cannonballs on a side. 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 