clear X K i j

N = 100;

X = zeros(N,N);

X(:,1)=ones(N,1);

for i = 2:N
    X(:,i) = X(:,i-1);
    for j = i:i:N
        X(j,i) = mod(X(j,i)+1,2);
    end
end

K = sum(X(:,N))
spy(X)