#define LED_1 1
#define LED_2 2
#define LED_4 4
#define LED_8 8

void setup() {
  pinMode(LED_1, OUTPUT);
  pinMode(LED_2, OUTPUT);
  pinMode(LED_4, OUTPUT);
  pinMode(LED_8, OUTPUT);
}

void loop() {
  for (int i = 0; i < 16; i++) {
    // Control LED_1
    if (i % 2 != 0)
      digitalWrite(LED_1, HIGH);
    else
      digitalWrite(LED_1, LOW);

    // Control LED_2
    if (i % 4 >= 2)
      digitalWrite(LED_2, HIGH);
    else
      digitalWrite(LED_2, LOW);

    // Control LED_4
    if (i % 8 >= 4)
      digitalWrite(LED_4, HIGH);
    else
      digitalWrite(LED_4, LOW);

    // Control LED_8
    if (i % 16 >= 8)
      digitalWrite(LED_8, HIGH);
    else
      digitalWrite(LED_8, LOW);

    // Delay for observation
    delay(1000);
  }
}