input: def find_odd_collatz_sequence(n):
      """
      Given a positive integer n, return a list that contains the odd numbers in the collatz sequence, in ascending order.
  
      The Collatz conjecture posits a sequence determined as follows: start with any positive integer n. For each subsequent term, if the current term is even, divide it by two; if it is odd, multiply it by three and add one. The sequence will always reach the value 1 regardless of the starting point.
  
      Note:
          1. Collatz(1) results in [1].
          2. The returned list must be sorted in ascending order.
  
      For example:
      find_odd_collatz_sequence(5) returns [1, 5] # The observed Collatz sequence for starting value 5 is [5, 16, 8, 4, 2, 1], with the odd numbers being 1 and 5.
      """
output:     
      odd_numbers = set()
      while n != 1:
          if n % 2 == 1:
              odd_numbers.add(n)
              n = 3 * n + 1
          else:
              n //= 2
      odd_numbers.add(1)  # Include 1 which is always in the sequence
  
      return sorted(odd_numbers)
  