The Collatz Conjecture states that for any natural number n, if n is even, divide it by 2. If n is odd, multiply it by 3 and add 1. If you repeat the process continuously for n, n will eventually reach 1.
For example, if n = 20, the resulting sequence will be:
[20, 10, 5, 16, 8, 4, 2, 1] 
Write a program that will output the length of the Collatz Conjecture for any given n. In the example above, the output would be 8.
For more reading see: http://en.wikipedia.org/wiki/Collatz_conjecture
def collatz(n):
  step = 1
  while n!= 1:
    n = [n//2, (n*3)+1][n%2]
    step += 1
  return step



def collatz(n):
  step = 1
  while n!= 1:
    n = [n//2, (n*3)+1][n%2]
    step += 1
  return step


