Information and Coding Theory

Hy,

I have a problem in Matlab Coding. My problem is I want to add parity bits on the position of power of 2 and data bits on the position that are not power of 2. I want to make it generic. In my case its work for n=3;total parity bit=2;length of codeword=5.

What if n=4;total parity bit=3 (on position 1,2,4) and length of codeword = 7

can somone guide me.

Thanks