Question

I take no credit for this challenge at all. It’s Project Euler problem 6:

The sum of the squares of the first ten natural numbers is,
1² + 2² + … + 10² = 385

The square of the sum of the first ten natural numbers is,
(1 + 2 + … + 10)² = 55² = 3025

Hence the difference between the sum of the squares of the first ten natural
numbers and the square of the sum is 3025 − 385 = 2640.

Find the difference between the sum of the squares of the first one hundred
natural numbers and the square of the sum.

I became interested in some code golfing here when I noticed my solution (in Python) was very, very short. I want to see how some other languages (perl, I’m looking at you!) can bring it in this simple problem.

So, what is the shortest possible way to solve this problem? Shortest means fewest characters in source code.

NOTE: bonus points for solving for the first n natural numbers.

Answer 1

Almost Any Language: 20 chars.

(n*n-1)*(3*n+2)*n/12