int zahlen[] = {11,12,13};
void setup() {
pinMode(11, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13,OUTPUT);
for(int i=0; i<3; i++){
  // put your setup code here, to run once:
digitalWrite(zahlen[i], HIGH);
delay(1000);
}
for(int i=0; i<3; i++){
  // put your setup code here, to run once:
digitalWrite(zahlen[i], LOW);
delay(1000);
}
}

void loop() {
  // put your main code here, to run repeatedly:

}