
    In a complex urban traffic network, determine the total number of potential traffic flow intersection points at the nth tier of complexity, where each new tier adds intersection points by connecting with all previous tiers' traffic patterns in a pyramidal structure. The traffic flow complexity grows such that each new tier n creates intersection points with all points from tiers 1 to (n-1), forming a three-dimensional traffic flow pattern.
    

    
def tetrahedral_number(n):
    """
    In a complex urban traffic network, determine the total number of potential traffic flow intersection points at the nth tier of complexity, where each new tier adds intersection points by connecting with all previous tiers' traffic patterns in a pyramidal structure. The traffic flow complexity grows such that each new tier n creates intersection points with all points from tiers 1 to (n-1), forming a three-dimensional traffic flow pattern.
    

    """
def tetrahedral_number(n):
    """
    In a complex urban traffic network, determine the total number of potential traffic flow intersection points at the nth tier of complexity, where each new tier adds intersection points by connecting with all previous tiers' traffic patterns in a pyramidal structure. The traffic flow complexity grows such that each new tier n creates intersection points with all points from tiers 1 to (n-1), forming a three-dimensional traffic flow pattern.
    

    """
    return n * (n + 1) * (n + 2) / 6