
    In a transit authority's maintenance scheduling system, determine the total number of inspection points that need to be checked during the nth comprehensive maintenance interval, where each successive interval follows a decagonal pattern of increasing complexity. The maintenance schedule follows a systematic progression where the nth interval's inspection points form a decagonal pattern, requiring technicians to plan resources accordingly.
    

    
def is_num_decagonal(n):
    """
    In a transit authority's maintenance scheduling system, determine the total number of inspection points that need to be checked during the nth comprehensive maintenance interval, where each successive interval follows a decagonal pattern of increasing complexity. The maintenance schedule follows a systematic progression where the nth interval's inspection points form a decagonal pattern, requiring technicians to plan resources accordingly.
    

    """
def is_num_decagonal(n):
    """
    In a transit authority's maintenance scheduling system, determine the total number of inspection points that need to be checked during the nth comprehensive maintenance interval, where each successive interval follows a decagonal pattern of increasing complexity. The maintenance schedule follows a systematic progression where the nth interval's inspection points form a decagonal pattern, requiring technicians to plan resources accordingly.
    

    """
    return 4 * n * n - 3 * n