int Pins[3]    = {2, 3, 4};
int Delays[3]  = {200, 500, 900};
int Millis[3]  = {0, 0, 0};
bool States[3] = {false, false, false};

void Blink(int i) {
  if (millis() - Millis[i] >= Delays[i]) {
    Millis[i] = millis();
    States[i] = !States[i];
    digitalWrite(Pins[i], States[i]);
  }
}

void setup() {
  for (int j=0; j<=2; j++) {
    pinMode(j, OUTPUT);
  }
}

void loop() {
  for (int k=0; k<=2; k++) {
    Blink(k);
  }
}