how to write a loop

I would like to obtain t values according to i parameters. If i=1, it should return just t1. If i=3, it should return t1, t2 and t3. If i=5, it should return t1,t2,t3,t4 and t5 and so on. How can write this part into a loop??

clear ; clc; 
n = 8; r = 2; h = 5; p=3;
Ang_seg = 360/n; 
    for i=1:n
        Xni(i) = r*cos((i-1)*Ang_seg*pi/180); 
        Yni(i) = r*sin((i-1)*Ang_seg*pi/180); 
        Zni(i) = 0;
        Cbottom = [Xni' Yni' Zni'];             

          Xnk(i) = Xni(i);                                          
          Ynk(i) = Yni(i);                      
          Znk(i) = h;
          Ctop = [Xnk' Ynk' Znk'];
      end

%how to write this part into a loop:
        for i=1
            t1 = ( Xni(i+1) - Xni(i) ) / ( ( Xnk(i+1) - Xni(i) ) - ( Xnk(i) - Xni(i+1) ) );
        end

          for i=3
              t1 = ( Xni(i-1) - Xni(i-2) ) / ( ( Xnk(i) - Xni(i-2) ) - ( Xnk(i+5) - Xni(i-1) ) );
              t2 = ( Xni(i) - Xni(i-2) ) / ( ( Xnk(i) - Xni(i-2) ) - ( Xnk(i-2) - Xni(i) ) );
              t3 = ( Xni(i+1) - Xni(i-2) ) / ( ( Xnk(i) - Xni(i-2) ) - ( Xnk(i-1) - Xni(i+1) ) );
          end

          for i=5
              t1 = ( Xni(i-3) - Xni(i-4) ) / ( ( Xnk(i-1) - Xni(i-4) ) - ( Xnk(i+2) - Xni(i-4) ) );
              t2 = ( Xni(i-2) - Xni(i-4) ) / ( ( Xnk(i-1) - Xni(i-4) ) - ( Xnk(i+3) - Xni(i-2) ) );
              t3 = ( Xni(i-1) - Xni(i-4) ) / ( ( Xnk(i-1) - Xni(i-4) ) - ( Xnk(i-4) - Xni(i-1) ) );
              t4 = ( Xni(i) - Xni(i-4) ) / ( ( Xnk(i-1) - Xni(i-4) ) - ( Xnk(i-3) - Xni(i) ) );
              t5 = ( Xni(i+1) - Xni(i-4) ) / ( ( Xnk(i-1) - Xni(i-4) ) - ( Xnk(i-2) - Xni(i+1) ) );
          end

Answer 1

[Matt Fig]

Instead of using:

for i=1

use

if i==1

(And it is generally not recommended to mask MATLAB functions in your code, such as the function i.)