
    As a school counselor organizing weekly group intervention sessions, you need to determine the total number of at-risk students that can be accommodated in a hexagonal seating arrangement for week n of the semester, where students are added in expanding hexagonal layers around a central student. Each week's arrangement follows the centered hexagonal number pattern, where the number of students increases according to this sequence to maintain effective group dynamics.
    

    
def centered_hexagonal_number(n):
    """
    As a school counselor organizing weekly group intervention sessions, you need to determine the total number of at-risk students that can be accommodated in a hexagonal seating arrangement for week n of the semester, where students are added in expanding hexagonal layers around a central student. Each week's arrangement follows the centered hexagonal number pattern, where the number of students increases according to this sequence to maintain effective group dynamics.
    

    """
def centered_hexagonal_number(n):
    """
    As a school counselor organizing weekly group intervention sessions, you need to determine the total number of at-risk students that can be accommodated in a hexagonal seating arrangement for week n of the semester, where students are added in expanding hexagonal layers around a central student. Each week's arrangement follows the centered hexagonal number pattern, where the number of students increases according to this sequence to maintain effective group dynamics.
    

    """
    return 3 * n * (n - 1) + 1