M-file to find primes < 5000

% M-file to find primes < 5000

r=11;
p=[2,3,5,7];
i=4; %i counts the number of primes so far
while r<5000
s=3;
while s*s<=r & rem(r,s)>0
s=s+2;
end;
if rem(r,s)>0
i=i+1;
p(i)=r;
end;
r=r+2;
end;