def int_to_bits_indexes(n):
    """Return the list of bits indexes set to 1.

    :param n: the int to convert

    :type n: int

    :return: a list of the indexes of bites sets to 1
    :rtype: list
    """
    L = []
    i = 0
    while n:
        if n % 2:
            L.append(i)
        n //= 2
        i += 1
    return L