
    In a city-wide delivery network using hexagonal zone divisions for route optimization, calculate the total number of delivery zones covered when expanding outward to the nth tier from a central hub, where each new tier forms a larger hexagonal pattern around previous tiers. Design a function that determines the cumulative count of delivery zones up to a specified tier n, enabling efficient coverage analysis and route distribution across the expanding hexagonal grid system.
    

    
def hexagonal_num(n):
    """
    In a city-wide delivery network using hexagonal zone divisions for route optimization, calculate the total number of delivery zones covered when expanding outward to the nth tier from a central hub, where each new tier forms a larger hexagonal pattern around previous tiers. Design a function that determines the cumulative count of delivery zones up to a specified tier n, enabling efficient coverage analysis and route distribution across the expanding hexagonal grid system.
    

    """
def hexagonal_num(n):
    """
    In a city-wide delivery network using hexagonal zone divisions for route optimization, calculate the total number of delivery zones covered when expanding outward to the nth tier from a central hub, where each new tier forms a larger hexagonal pattern around previous tiers. Design a function that determines the cumulative count of delivery zones up to a specified tier n, enabling efficient coverage analysis and route distribution across the expanding hexagonal grid system.
    

    """
    return n * (2 * n - 1)