int LED1 = 13;
int LED2 = 9;

void setup() {

pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
}

void loop() {
digitalWrite(LED1, HIGH);
delay(50);
digitalWrite(LED1, LOW);
delay(100);
digitalWrite(LED2, HIGH);
delay(50);
digitalWrite(LED2, LOW);
delay(100);
}