Pratt sequence generator in python

pratt.py

# Original script by Damian Yerrick
# http://stackoverflow.com/a/25964763
def pratt(max_size):
    """Generate a sorted list of products of powers of 2 and 3 below max_size"""
    # for https://stackoverflow.com/q/25964453/2738262
    products = []
    pow3 = 1  # start with q = 0
    while pow3 <= max_size:
        # At this point, pow3 = 3**q, so set p = 0
        pow2 = pow3
        while pow2 <= max_size:
            # At this point, pow2 = 2**p * 3**q
            products.append(pow2)
            pow2 = pow2 * 2  # this is like adding 1 to p
        # now that p overflowed the maximum size, add 1 to q and start over
        pow3 = pow3 * 3

    # the Pratt sequence is the result of this process up to the given size
    return sorted(products)