int i;
void setup()
{
// put your setup code here, to run once:
for (i = 2; i <= 9; i++){
pinMode(i, OUTPUT);
}
}
void loop()
{
// put your main code here, to run repeatedly:
for (i=2; i<=9; i++)
digitalWrite(i,1);
digitalWrite(11-i,1);
delay(250);
digitalWrite(i,0);
digitalWrite(11-i,0);
}