const byte BUTTON = 2;
const byte LED_START = 3;

const byte LEDS = 4;

boolean autoMode = true;
const int autoDelay = 500;
byte val = 0;
int buttonState = false;
int lastButton  = false;

void setup()
{
  Serial.begin(9600);

  pinMode(BUTTON, INPUT);

  for (byte i = 0; i < LEDS; ++i)
    pinMode(LED_START + i, OUTPUT);
}

void loop()
{
  buttonState = digitalRead(BUTTON);

  if ((buttonState != lastButton) || autoMode)
  {
    if ((buttonState == HIGH) || autoMode)
    {
      if (autoMode)
        delay(autoDelay);

      Serial.print("Button press: ");
      Serial.print("val = ");
      Serial.println((int)val);
      val += 1;

      Serial.println(pow(2, LEDS));
      val %= (byte)(pow(2, LEDS));
    }
  }

  lastButton = buttonState;

  for (byte i = 0; i < LEDS; ++i)
  {
    Serial.print("LED");
    Serial.print((int)i);
    Serial.print(" = ");
    Serial.println(bitRead(val, i));

    digitalWrite(LED_START + i, bitRead(val, i));
  }
}