Substituting Value into Unknown Inside Matrices

Recently I got stuck on performing such a work, which is substituting into matrices I've tried over "Subs()" but it seems to be having wrong output

{ x=[1 3 5 7 9];

n=2;

 syms a;
for i=1:n %row %n=2
    for j=1:n %col %n=2

         A(i,j)=(a^(2*(n)-i-j+2))    

    end

end

 syms a;
 syms b;

 for k=1
     for l=1:n+1

         C(k,l)=b*(a)^(n)
         n=n-k;             %when = 2 ,C = [ x^2*y, x*y, y]
     end

 end
 c=transpose(C)

 %   totalsub=0;
   totalsub=subs(A,a,x)

% g=poly2sym(A) % X=(inv(A))*(c)

 }
when a 3x3 matrix times with 3x1 matrix it should be 3x3 but..
Even at the subs part...