N=50;
y=zeros(1,N);
n=[0:9];

y(1:10)=2-2.^(-n);
y(11:N)=(2^10-1)./(2.^[10:N-1]);
stem(y)
pause

h=2.^(-[0:N-1]);
x=ones(1,10);
yy=conv(h,x);
stem(yy,'m')

stem(y-yy(1:N))