This means the controller is not connecting to your PS3. Ensure the PS3 is powered on (red or green light should be seen on front of PS3, if not check plugs and switch on at back).
Press the PS3 button on the controller (circular button between start and select). If the controller still does not sync (connect) to the PS3, all lights will flash on and off. In order to sync the controller and the PS3, the controller must be plugged into the front of the PS3 using the black USB cable provided. Once this is done, press the PS button and they will connect. You may unplug the cable then if you wish.