int leds[] = {2, 4, 5}; 
int delays[] = {2000, 1600, 1200, 800, 400, 200};

void setup() {
  for (int i = 0; i < 3; i++) {
    pinMode(leds[i], OUTPUT);
  }
}

void loop() {
  int j = 0;  // índice  delays
  while (true) {  // Bucle 
    for (int i = 0; i < 3; i++) {
      digitalWrite(leds[i], HIGH);
      delay(delays[j]);  // val delay act
      digitalWrite(leds[i], LOW);
      if (i < 2) {
        delay(400);
      }
    }
    
    if (j < 5) {
      j++;
    }
  }
}