void setup() {
    
  for (int i = 2; i < 10; i++) {
    pinMode(i, OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int i = 2; i < 10; i++) {
    digitalWrite(i, HIGH); 
    delay(30);
    digitalWrite(i, LOW);  
  }
}