const int ledPins[] = {2, 3, 4, 5};  // Digital pins connected to LED cathodes

void setup() {
  for (int i = 0; i < sizeof(ledPins) / sizeof(ledPins[0]); i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // Turn on LEDs in sequence
  for (int i = 0; i < sizeof(ledPins) / sizeof(ledPins[0]); i++) {
    digitalWrite(ledPins[i], HIGH);
    delay(500);  // Adjust delay as needed
    digitalWrite(ledPins[i], LOW);
  }

  // Turn off all LEDs
  for (int i = 0; i < sizeof(ledPins) / sizeof(ledPins[0]); i++) {
    digitalWrite(ledPins[i], LOW);
  }

  delay(500);  // Delay before starting the sequence again
}