Write a python function to count numbers whose oth and nth bits are set.
def count_Num(n): 
    if (n == 1): 
        return 1
    count = pow(2,n - 2) 
    return count 
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a python function to count numbers whose oth and nth bits are set.
def count_Num(n): 
    if (n == 1): 
        return 1
    count = pow(2,n - 2) 
    return count [/INST]assert count_Num(2) == 1
assert count_Num(3) == 2
assert count_Num(1) == 1</s>