const uint8_t led[5] = { 3,5,6,9,10 };
// led pins array (pwm)

void setup() {
  for (uint8_t i = 0; i < 5; i++) {
    pinMode(led[i], OUTPUT);
  }
}

void loop() {
  for (uint8_t i = 0; i < 5; i++){
    int pin = led[i];
    for (uint8_t j = 0; j < 50; j++) {
      delay(1);
      analogWrite(pin, j * 2);
    }
  }

  delay(200);
  
  for (int z = 0; z < 5; z++) {
    int pin = led[4 - z];
    analogWrite(pin, 0);
  }

  delay(100);
}