int led1=13;
int led2=12;
int led3=11;
void setup()
{
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
digitalWrite(led1, HIGH);
Serial.println("led1 is on"); 
delay(100);
digitalWrite(led2, HIGH);
Serial.println("led2 is on");  
delay(100);
digitalWrite(led3, HIGH);
Serial.println("led3 is on");  
delay(100);
digitalWrite(led1, LOW);
Serial.println("led1 is off");  
delay(200);
digitalWrite(led2, LOW);
Serial.println("led2 is off");  
delay(200);
digitalWrite(led3, LOW);
Serial.println("led3 is off");  
delay(200);
}