Project Euler: Problem 6

Challenge:

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.

Programming Language:

LISP

Solution:

(defun sqr(x)
  (* x x))

(defun sum-sqr-diff(lim)
  (- (sqr (apply #'+ (loop for x from 1 to lim collect x)))
     (apply #'+ (mapcar #'sqr (loop for x from 1 to lim collect x)))))

Overview:

Coming soon…