How do I let a initial vector change depending on input?

I want to display a table for error solutions to a Hilbert matrix n=5-13. I initialized a ones vector but it will not accept a change in size even inside a for loop. Here is a sample of my code:

function T=object(n) 
    for i=1:length(n)
     A=hilb(n(i));
     x_true=ones(n(i),1);
    b=A.*x_true;
%List of variables for the table.  Reiterate to avoid overwriting.
    n=n(i);
    for j=1:length(n)
       var1=something
   end
    for j=1:length(n)
       var2=something
   end
    for j=1:length(n)
       var3=something
   end
T=table(n,var1,var2,var3);
summary(T)
    end
end