Vectorized version,
sz = 20; % matrix size, square, positive integer
difference = 2; % width of bands, positive integer 1 <= x <= (sz/2)-1
% Create matrix
nestedMat = (sz-difference*2):-difference*2:0;
layers = arrayfun(@(m){padarray(ones(m),(sz-m)*[.5,.5])},nestedMat);
A = mod(sum(cat(3,layers{:}),3),2);
% Plot it
imagesc(A)
axis equal
Loop version,
sz = 20; % matrix size, square, positive integer
difference = 2; % width of bands, positive integer 1 <= x <= (sz/2)-1
% Create matrix
nestedMat = (sz-difference*2):-difference*2:0;
layers = zeros(sz);
for i = 1:numel(nestedMat)
layers = layers + padarray(ones(nestedMat(i)), (sz-nestedMat(i))*[.5,.5]);
end
A = mod(layers,2);
% Plot it
imagesc(A)
axis equal