primes0(m)

function x = primes0(m)               
%primes  nombres premiers <= m              
%        x = primes0(m)             
    
    x = 1:m; x(1)=0;                     
    for i = 2:fix(m/2)                   
      if x(i) ~= 0                       
        for j = 2*i:i:m                  
          x(j) = 0;                      
        end;                             
      end;                               
    end;    
    x = x(x>0);