int n;
bool dON;

void setup() {
Serial.begin(9600);
pinMode(2, OUTPUT);
}

void loop () {
n = n + 1;
if(n % 4 == 0 || n % 7 == 0) {
  dON = true;
} else {
 dON = false;
}

if (dON == true) {
  digitalWrite(2, HIGH);
} else {
  digitalWrite(2, LOW);
}
if (n >= 300)
n = 0;
Serial.println(n);
delay(100);
}