how to sum matrices in a for loop

hi every body. suppose the bellow code. this code give me 16 matrices. how can i sum all of this matrices by using these for-loops?

for i=1:4
    for j=1:4
        a=[0 1:1 0];
        b=[1 0:0 1];
        x=i*a+j*b;
    end
end

Answer 1

[David Hill]

I assume you just want to add the calculated x-matrix with itself during each loop iteration.

x=zeros(2);
for i=1:4
    for j=1:4
        a=[0 1:1 0];
        b=[1 0:0 1];
        x=x+i*a+j*b;
    end
end