
    Write a function to determine the number of possible professional interest profiles where professionals have an equal number of matching interests in their primary and secondary skill sets, given that each professional's complete profile consists of 2n binary indicators representing different career interests split equally between primary and secondary skills.
    

    
def count_binary_seq(n):
    """
    Write a function to determine the number of possible professional interest profiles where professionals have an equal number of matching interests in their primary and secondary skill sets, given that each professional's complete profile consists of 2n binary indicators representing different career interests split equally between primary and secondary skills.
    

    """
def count_binary_seq(n):
    """
    Write a function to determine the number of possible professional interest profiles where professionals have an equal number of matching interests in their primary and secondary skill sets, given that each professional's complete profile consists of 2n binary indicators representing different career interests split equally between primary and secondary skills.
    

    """
    nCr = 1
    res = 1
    for r in range(1, n + 1):
        nCr = nCr * (n + 1 - r) / r
        res += nCr * nCr
    return res