How to add a number of transfer function

 Dear All
I am trying to get transfer function of  a circuit, my question is how to sum Rn in the for loop rather than using this command 

R=Rn(1)+Rn(2)+Rn(3)+Rn(4)+Rn(5)+Rn(6)+Rn(7)+Rn(8)+Rn(9)+Rn(N)
thanks in advance

 close all
  clear all
  clc
  format short
  s=tf('s')
  RL=100e3    % leakge resistor
  %define the parameters
  L=50e-9      % inductance the unit should be converted from nano
  Ri=1.883e-3
  T=1.67       % tau
  C=1130       % capacitor
  N=10       % the number of RC 
  Zm=(Ri+L*s+1/C*s)    % resitor, inductance and capacitor  connected in series
  for n=1:N
  Rn(n)=(2*T*C*s)/(n^2*pi^2*1)
  Cn=C/2
  end
  R=Rn(1)+Rn(2)+Rn(3)+Rn(4)+Rn(5)+Rn(6)+Rn(7)+Rn(8)+Rn(9)+Rn(N)
   Zs=R/(1+R*Cn*s)

Answer 1

[Mischa Kim]

Salim, you could simply do

 ...
 R = 0
 for n = 1:N
    R  = R + (2*T*C*s)/(n^2*pi^2*1)
    Cn = C/2
 end
 Zs = R/(1+R*Cn*s)

[Matlab & Simulink]

thanks