boolean buttonWasUp = true;
boolean ledEnabled = false;
boolean buttonIsUp;
unsigned long timer;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(13, OUTPUT);
  pinMode(4, INPUT_PULLUP);
  timer = millis();
}

void loop() {
   //buttonIsUp = !digitalRead(4);
   if (buttonWasUp && !buttonIsUp) {
      if  ((millis() - timer > 10)) {
      buttonIsUp = !digitalRead(4);
      
      digitalWrite(13, buttonIsUp);
      }
    
      if (!buttonIsUp) {
         ledEnabled = !ledEnabled;
         digitalWrite(13, ledEnabled);
      }
   }
   buttonWasUp = buttonIsUp;
   Serial.println(buttonIsUp);
}