int ledpin = 8;
int delaytime[] = {2000};
int index = 0;

void setup() {
  pinMode(ledpin, OUTPUT);

}

void loop() {
 digitalWrite(ledpin, HIGH);
 delay(delaytime[index]);
 digitalWrite(ledpin, LOW);
 delay(delaytime[index]);

 index++;
 if (index >= 4){
  index = 0;
 }
}