function y = convn(v,n)
% y = conv(v,n)
% Convolution of vector y with itself n times
if  n<1
  disp('Invalid n');
elseif n == 1
  y = v;
else
 V = v;
 for i = 1:n-1
  V = conv(v,V);
 end
y = V;
end