I think the random tests are not working. I've passed the basic test easily, but the random tests array expect to multiply every second element by 4. Here is my error message:
the list second element: 2093
my returned list: [2827, 4186, -868, 2106, -1845, 1650, 2088, -1964, -1417, -3548, 2779, -2440, 1063, 3352, 1144, -4252, -2431, -3530]
should equal [2827, 8372, -868, 4212, -1845, 3300, 2088, -3928, -1417, -7096, 2779, -4880, 1063, 6704, 1144, -8504, -2431, -7060]