E.g., here is a possible outline
n = 30; % the number of iterations
M = rand(5,5); % some initial matrix
for k=1:n
M = 2*M; % or some other function involving M
end
If you need to save all the intermediate results, then something like this:
n = 30; % the number of iterations
M = zeros(5,5,n+1);
M(:,:,1) = rand(5,5); % some initial matrix
for k=2:n+1
M(:,:,k) = 2*M(:,:,k-1); % or some other function involving M(:,:,k-1)
end
