a11=[ 0 0 0 0 0 0 0 0 0 0 1;  0 0 0 0 0 0 0 0 0 1 0];n=11
a22=zeros(n-2, n);
a=[a11;a22];
for i=3:n
   for j=1:n-1
      a(i,j)=a(i-1,j+1)-(i-2)*a(i-2,j);
      a(i,n)=-(i-2)*a(i-2,n);
   end
   end