int ledPins[] = {0,1,2,3,4,5,6,7};
int size = 8;
int ledSize = 3;
int delayTime = 50;
void setup() {
 for(int i = 0;i<size;i++) {
  pinMode(ledPins[i], OUTPUT);
 }

}

void loop() {



  for(int i = 0;i<size;i++) {
      for(int j = 0;j < ledSize;j++) {
        digitalWrite(ledPins[(i+j >= size  ? i+j - size - 1 : i+j )  ], HIGH);
      }
      digitalWrite(ledPins[i == 0? size - 1 :i - 1], LOW);
      delay(delayTime);
    }
  delay(delayTime);
  // put your main code here, to run repeatedly:

}