# Problem Definition

Available at Sum square difference

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.

# Implementation

open System | |

let squareOfSum n = | |

let i = n*(n+1)/2 | |

i*i | |

let sumOfSquare n = | |

[1..n] | |

|> List.fold (fun acc x -> acc + x*x) 0 | |

let solveEuler6 N = | |

(squareOfSum N)- (sumOfSquare N) |