int ledR=13;
int ledV=12;
int ledB=11;
int ledJ=6;
int ledO=5;
int ledVi=4;

int leds[]={ledR, ledV, ledB, ledJ, ledO, ledVi};
int numLed=6;

void setup() {
  // put your setup code here, to run once:
for (int i=0; i<numLed; i++){
  pinMode(leds[i],OUTPUT);
}
}

void loop() {
  // put your main code here, to run repeatedly:
for (int i=0; i<=numLed; i++){
  digitalWrite(leds[i],1);
  delay(100);
  digitalWrite(leds[i],0);
  delay(100);
}
for (int i=numLed - 1; i>=0; i--){
  digitalWrite(leds[i],1);
  delay(100);
  digitalWrite(leds[i],0);
  delay(100);
}
for (int i=0; i<=numLed/2; i++){
  digitalWrite(leds[i],1);
  digitalWrite(leds[numLed-1-i],1);
  delay(100);
  digitalWrite(leds[i],0);
  digitalWrite(leds[numLed-1-i],0);
}
}