int ledPin[] = {13, 12, 11,10};
int ledDelay[4]={8000, 4000,2000, 1000};
// declare other required variables
int ledState[4] = {0, 0, 0, 0};
int currTime =0;

void setup() {
  for(int i=0;i<4;i++){
    // initialize lastChangeTimes
    // set pin mode for ledPins
    pinMode(ledPin[i], OUTPUT);
    digitalWrite(ledPin[i], ledState[i]);
  }
  currTime+=1000;
    
}


void loop() {
  // toggling pin states
  for(int i=0;i<4;i++){
    if (currTime%ledDelay[i] == 0) {
    ledState[i] = ~ledState[i];
    }
  }

  //setting pins
  for(int i=0;i<4;i++){
    digitalWrite(ledPin[i], ledState[i]);
  }
  
  //modifying current time
  currTime+=1000;
  if (currTime==16000) {
  currTime=0;
  }
  delay(1000);
}