const int pindiod[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9}; 
const int diodnumber = 9; 

void setup()
{
  for(int a = 0; a < diodnumber; a++)
    {
      pinMode(pindiod[a], OUTPUT);  
    } 
}

void loop() 
{ 
  for(int a = 0; a < diodnumber; a++)
    {
      digitalWrite(pindiod[a], true );
      delay(500);
      digitalWrite(pindiod[a], !true );
    }
}