SOURCE

function fib(num) {
  var arr = [];
  if (num == 1) {
    return arr = [1];
  } else if (num == 2) {
    return arr = [1, 1];
  } else {
    arr = [1, 1];
    for (var i = 2; i < num; i++) {
			arr[i] = arr[i-1] + arr[i-2];
    }
    return arr;
  }
}
console.log( fib(8));