# c08ex04.py
#    Syracuse sequence
#    Note: Let me know if you find a starting value that doesn't go to 1 :-).

def main():
    print "This program outputs a Syracuse sequence\n"
    n = input("Enter the initial value (an int >= 1): ")
    while n != 1:
        print n,
        if n % 2 == 0:
            n = n / 2
        else:
            n = 3 * n + 1
    print 1

if __name__ == '__main__':
    main()