int pointer = 13;
int i = 1;
int counter = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(pointer, HIGH);
  delay(30);
  digitalWrite(pointer, LOW);

  pointer = pointer - i;

  if(pointer <=9 || pointer >=13){
    i = -i;
  }
  delay(100);
}