
    Given a sequence of patient health indicators that form hexagonal clusters where each progression stage adds a complete outer layer of new interconnected indicators, develop a function to calculate the total number of connected health markers at the nth stage of disease progression analysis. Each stage follows a centered hexagonal pattern, starting with one central indicator and expanding outward, where the count of indicators at each stage helps medical professionals track and predict disease development phases.
    

    
def centered_hexagonal_number(n):
    """
    Given a sequence of patient health indicators that form hexagonal clusters where each progression stage adds a complete outer layer of new interconnected indicators, develop a function to calculate the total number of connected health markers at the nth stage of disease progression analysis. Each stage follows a centered hexagonal pattern, starting with one central indicator and expanding outward, where the count of indicators at each stage helps medical professionals track and predict disease development phases.
    

    """
def centered_hexagonal_number(n):
    """
    Given a sequence of patient health indicators that form hexagonal clusters where each progression stage adds a complete outer layer of new interconnected indicators, develop a function to calculate the total number of connected health markers at the nth stage of disease progression analysis. Each stage follows a centered hexagonal pattern, starting with one central indicator and expanding outward, where the count of indicators at each stage helps medical professionals track and predict disease development phases.
    

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