def coll(listOfNumbers):
   @memoize
   def collAndAdd(resultsList, idx, curr):
      if idx == len(listOfNumbers):
          return;
      else:
          first = rest[idx]
          resultsList.push(first * curr)
          collAndAdd(resultsList, idx + 1, first * curr)
          collAndAdd(resultsList, idx + 1, curr)

   results = []
   collAndAdd(results, 0, 1)
   return results