def next_collatz_seq(current_number):
    """Returns the next collatz sequence number after current_number"""
    next_number = 0
    if current_number == 1:
        next_number = 0
    elif current_number % 2 == 0:
        next_number = current_number / 2
    else:
        next_number = (current_number * 3) + 1

    return next_number