prendimos tres leds

void setup() {

  pinMode(1, OUTPUT);

  pinMode(2, OUTPUT);

  pinMode(3, OUTPUT);

}

void loop() {

  digitalWrite(1, HIGH);

  delay(3000);

  digitalWrite(1, LOW);

  delay(3000);

  digitalWrite(2, HIGH);

  delay(3000);

  digitalWrite(2, LOW);

  delay(3000);

  digitalWrite(3, HIGH);

  delay(3000);

  digitalWrite(3, LOW);

  delay(3000);

  digitalWrite(1, HIGH);

  digitalWrite(2, HIGH);

  digitalWrite(3, HIGH);

  delay(3000);

  digitalWrite(1, LOW);

  digitalWrite(2, LOW);

  digitalWrite(3, LOW);

  delay(3000);

  digitalWrite(3, HIGH);

  delay(3000);

  digitalWrite(3, LOW);

  delay(3000);

  digitalWrite(2, HIGH);

  delay(3000);

  digitalWrite(2, LOW);

  delay(3000);

  digitalWrite(1, HIGH);

  delay(3000);

  digitalWrite(1, LOW);

  delay(3000);

  digitalWrite(1, HIGH);

  digitalWrite(2, HIGH);

  digitalWrite(3, HIGH);

  delay(3000);

  digitalWrite(1, LOW);

  digitalWrite(2, LOW);

  digitalWrite(3, LOW);

  delay(3000);

}