
    As a school administrator tracking student attendance patterns, you need to develop a system to analyze dropout risk by calculating the cumulative attendance impact over time. Starting with an initial class size, the attendance typically decreases by 2 students at regular intervals throughout the semester. Calculate the total attendance impact by summing the sequence of attendance numbers, starting from the initial enrollment and subtracting 2 students each interval, until no more students remain or the pattern cannot continue. This calculation will help quantify the overall attendance pattern and identify potential intervention points for student retention efforts.
    

    
def sum_series(n):
    """
    As a school administrator tracking student attendance patterns, you need to develop a system to analyze dropout risk by calculating the cumulative attendance impact over time. Starting with an initial class size, the attendance typically decreases by 2 students at regular intervals throughout the semester. Calculate the total attendance impact by summing the sequence of attendance numbers, starting from the initial enrollment and subtracting 2 students each interval, until no more students remain or the pattern cannot continue. This calculation will help quantify the overall attendance pattern and identify potential intervention points for student retention efforts.
    

    """
def sum_series(n):
    """
    As a school administrator tracking student attendance patterns, you need to develop a system to analyze dropout risk by calculating the cumulative attendance impact over time. Starting with an initial class size, the attendance typically decreases by 2 students at regular intervals throughout the semester. Calculate the total attendance impact by summing the sequence of attendance numbers, starting from the initial enrollment and subtracting 2 students each interval, until no more students remain or the pattern cannot continue. This calculation will help quantify the overall attendance pattern and identify potential intervention points for student retention efforts.
    

    """
    if n < 1:
        return 0
    else:
        return n + sum_series(n - 2)