function y=etaylor(t)
   error= 1e-2;
   last = (1/ error) * t;
   y=0; term=1;
   for ii=0:last
       y    = y+term;
       term = (t * term)/(ii+1);
       fprintf('%8d %18.17f %10.17f \n',ii,term,y);
   end
  

% e**t  = 1 + t + t^2 /2! + ...
% a_n+1 = a_n  * t /(n+1);
%  term = term * t / (ii+1)  above
