1000
1000/2 = 500 odd numbered bulbs
(1000/2) /3 = ~166 (every odd bulb, and every third of those)
could be wrong, but thats whats off top of my head.
oh, 3rd switches bulbs back on? that would then be
500 + 166 = 666
hehe, is this a joke?
[ February 25, 2004: Message edited by: CL Gilbert ]