%close all; clear all; more off;
t = linspace(0,20,1000);

a0 = 1;
a(1) = 0;
a(2) = -a0/2;
x = a0*t.^0+a(1)*t.^1+a(2)*t.^2;

for n=1:50
   a(n+2) = -a(n)/((n+2)*(n+1)); 
    x = x + a(n+2)*t.^(n+2);
end

plot(t,x);
axis([0 20 -2 2])
hold on;
