For each number in an array, get the sum of its factors. Return an array of results.

function factorSum(arr){
  var result = [];
  for(var i = 0; i < arr.length; i++){
    var sum = 0;
    for(var j = 0; j < arr[i]; j++){
      if(arr[i] % j === 0){
        sum += j;
      }
    }
    result.push(sum);
  }
  return result;
}

factorSum([1,2,3,4]);
//[1,1,6,7]