Why is my code not doubling every odd index?

I’m trying to write a version of Luhn’s algorithm, but why is my code not doubling every odd index here? It seems to be doubling a pattern of index’s but i dont understand how it’s got that pattern from my code.

    const validateCred = (array) => {
      let removeLast = array.pop();
      let reversed = array.reverse();
      console.log(reversed);
      for (let i = reversed[0]; i < reversed.length; i++)
      if (reversed[i] % 2 !== 0) {
        reversed[i] *= 2;
      }
      console.log(reversed)




[ 0, 8, 6, 1, 0, 8, 0, 9, 7, 7, 6, 9, 3, 5, 4 ]
[ 0, 8, 6, 2, 0, 8, 0, 18, 14, 14, 6, 18, 6, 10, 4 ]

As you can see it’s doubling some of the digits, but not the odd ones.