impulse function

[brito\.rn]

Hi,

I need to plot a sequence of samples of a equation that has impulses.

The sequence is here:
x[n] = sum(m+1)*[impulse(n-2m)-impulse(n-2m-1)], with the sum of m from 0 to 10 
and n from 0 to 25.

A simple code for that can be:

for n = 0:25
        for m = 0:10
                x(n) = (m+1)*(impulse(n-(2*m))-impulse(n-(2*m)-1));
        endfor;
        plot(x(n));
endfor;

but, the problem is: the imput impulse function format is sys type. I don't 
have idea about how I can use this
sys format for my equation.

I need help about how I can plot that sequence with impulses.

regards,

Brito.