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Sunday, November 1, 2009

Solving Project Euler Problem #6

Problem Statement :
The sum of the squares of the first ten natural numbers is,
1**2 + 2**2 + ... + 10**2 = 385
The square of the sum of the first ten natural numbers is,(1 + 2 + ... + 10)**2 = 55*2 = 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.

Solution is -> (n(n+1)/2)**2 - (n*(n+1)*(2n+1))/6



(defn euler6 [n] (- (* (/ (* n (+ n 1)) 2) (/ (* n (+ n 1)) 2)) (/ (* n (+ n 1) (+ 1 (* n 2))) 6)))
(println (euler6 100))

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