Karl Steven
int ledPin[3]={21,22,23};
int i=0;


void setup(){

  for(i=0;i<3;i++){
    pinMode(ledPin[i], OUTPUT);
  randomSeed(analogRead(0));  
  }
}
void loop(){

  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], HIGH);
    delay(500);
    digitalWrite(ledPin[i], LOW);
    delay(500);
  }

  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], HIGH);
  }
  delay(500);
  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], LOW);
  }
  delay(500);
  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], HIGH);
  }
  delay(500);
  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], LOW);
  }
  delay(500);
  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], HIGH);
  }
  delay(500);
  for(i=0;i<3;i++){
    digitalWrite(ledPin[i], LOW);
  }
  delay(500);

  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], HIGH);
    delay(500);
    digitalWrite(ledPin[i], LOW);
    delay(500);
  }

  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], HIGH);
  }
  delay(500);
  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], LOW);
  }
  delay(500);
  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], HIGH);
  }
  delay(500);
  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], LOW);
  }
  delay(500);
  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], HIGH);
  }
  delay(500);
  for(i=3;i>=0;i--){
    digitalWrite(ledPin[i], LOW);
  }
  delay(500);

  int RLED = random(1,7);
  switch (RLED) {

    case 1:
      ON(21);ON(22);ON(23);
      break;
     case 2:
      ON(21); ON(23);ON(22);
      break;
     case 3:
      ON(22); ON(21);ON(23);
      break;
     case 4:
      ON(22); ON(23);ON(21);
      break;
     case 5:
      ON(23); ON(21);ON(22);
      break;
     case 6:
      ON(23); ON(22);ON(21);
      break;
      
  }
}

void ON(int pin){
  digitalWrite(pin, HIGH);
  delay(800);
  digitalWrite(pin, LOW);
  delay(800);

}