Arduino Uno LED Sample Program

int time = 500;
int inittime = 50;

void setup()                        // inital setup
{
  for(int i=9; i>=2; i--)           // Loops from i=9 down to and including i=2
  {
  pinMode(i, OUTPUT);               // sets pin i the digital pin as output
  delay(inittime);                  // waits for inittime
  }
}

void loop()
{

  for(int i=2; i<10; i++)           // Loops from i=2 up to but not including i=10
  {
  digitalWrite(i, LOW);             // sets the LED on
  delay(time);                      // waits for time
  digitalWrite(i, HIGH);            // sets the LED off
  delay(time);                      // waits for time
  }
}