int LEDPin [] = {0, 1, 2};
int LayerPin [] = {16, 17, 18, 19};

void setup()
{
  for(int pin = 0; pin < 16 ; pin++ )
  {
    pinMode(LEDPin[pin],OUTPUT);
    digitalWrite(LEDPin[pin],LOW);
  }
  // Set up LED Layers as output
  for(int layer = 0; layer < 4; layer++)
  {
    pinMode(LayerPin[layer], OUTPUT);
    digitalWrite(LayerPin[layer], HIGH);
  }
}

void loop()
{
  digitalWrite(LEDPin[0],HIGH);
  digitalWrite(LEDPin[1],HIGH);
  digitalWrite(LEDPin[2],HIGH);      
  
  digitalWrite(LayerPin[0],HIGH); 
  digitalWrite(LayerPin[1],HIGH); 
  digitalWrite(LayerPin[2],HIGH); 
  digitalWrite(LayerPin[3],HIGH);
}