Update Problem006.js (#1537)

Project-Euler/Problem006.js

@@ -1,11 +1,8 @@
 // https://projecteuler.net/problem=6
 
 export const squareDifference = (num = 100) => {
-  let sumOfSquares = 0
-  let sums = 0
-  for (let i = 1; i <= num; i++) {
-    sumOfSquares += i ** 2 // add squares to the sum of squares
-    sums += i // add number to sum to square later
-  }
+  let sumOfSquares = (num)*(num+1)*(2*num+1)/6
+  let sums = (num*(num+1))/2
+  
   return sums ** 2 - sumOfSquares // difference of square of the total sum and sum of squares
 }