int speed=200;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
for(int pin=2; pin<=6; pin=pin+1){
  pinMode(pin, OUTPUT);
  Serial.println(pin);
  delay(speed);
}
}

void loop() {
  for(int pin=2; pin<=6;pin=pin+1){
digitalWrite(pin, HIGH);
delay(500);
digitalWrite(pin, LOW);
Serial.println(pin);
delay(500);
  }

}