int ledPins[] = {23, 22, 21, 19, 18, 5, 4, 2};

void setup() {

    for (int pin = 0; pin < 8; pin++) {
        pinMode(ledPins[pin], OUTPUT);
    }
}

void loop() {

    for (int pin = 0; pin < 8; pin++) {
        digitalWrite(ledPins[pin], HIGH);
        delay(300); 
        digitalWrite(ledPins[pin], LOW);
    }
    delay(200);
}