int timer1_counter;

void setup() {
  pinMode(13, OUTPUT);
  noInterrupts();
  TCCR1A = 0;
  TCCR1B = 0;

  timer1_counter = 10000; //65535 - 62500 = 3035

  TCNT1 = timer1_counter;
  TCCR1B |= (1 << CS12);
  TIMSK1 |= (1 << TOIE1);
  interrupts();
}

ISR(TIMER1_OVF_vect)
{
  digitalWrite(13, digitalRead(13) ^ 1);
  TCNT1 = timer1_counter;
}

void loop() {}