
    Design a function that calculates the total number of learning objectives a student needs to master to reach a specific learning milestone, where each milestone level adds objectives across three dimensions: core concepts, practical skills, and real-world applications, forming a triangular pyramid of interconnected learning points. The milestone level is represented by n, and each new level builds upon all previous levels in a tetrahedral pattern.
    

    
def tetrahedral_number(n):
    """
    Design a function that calculates the total number of learning objectives a student needs to master to reach a specific learning milestone, where each milestone level adds objectives across three dimensions: core concepts, practical skills, and real-world applications, forming a triangular pyramid of interconnected learning points. The milestone level is represented by n, and each new level builds upon all previous levels in a tetrahedral pattern.
    

    """
def tetrahedral_number(n):
    """
    Design a function that calculates the total number of learning objectives a student needs to master to reach a specific learning milestone, where each milestone level adds objectives across three dimensions: core concepts, practical skills, and real-world applications, forming a triangular pyramid of interconnected learning points. The milestone level is represented by n, and each new level builds upon all previous levels in a tetrahedral pattern.
    

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