def printLexTo(n):
    val=1
    while True:
        if val<=n:
            print("{0:b}".format(val))
        if 2*val <= n:
            val *= 2
        else:
            # get the smallest 0 bit
            bit = (val+1) & ~val
            # set it to 1 and remove the remainder
            val = (val+1)//bit
            if val==1:
                # there weren't any 0 bits in the string
                break
 
printLexTo(23)

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