#! /usr/bin/python

# The Collatz conjecture

def collatz(n):
    " the function for collatz "
    if n % 2:
        return 1 + (n * 3)
    else:
        return int(n / 2)


## generate the series based on Collatz
def cseries(n):
  print(n)
  if n == 1:
      print ("done")
  else:
      cseries(collatz(n))

## see http://sahandsaba.com/python-iterators-generators.html
## x = collatzg(19)
## next(x)

def collatzg(n):
   yield n
   while n != 1:
     n = n / 2 if n % 2 == 0 else 3 * n + 1
     n = int(n)
     yield n


if __name__ == '__main__':
    import sys
    print (sys.argv)
    if len(sys.argv) > 1:
        for n in sys.argv[1:]:
            cseries(int(n))