sum_of_square.ml

let rec sum_of_square n =
if n = 0 then 0 else (n * n) + sum_of_square (n-1)

let test1 = sum_of_square 1 = 1
let test2 = sum_of_square 2 = 5
let test3 = sum_of_square 3 = 14
let test4 = sum_of_square 4 = 30