Sticking my nose in where it's not needed because I'm an insomniac tonight / this morning:
Picture a string of Christmas bulbs where the lights blink on and off in a regular timing, via a programmable box called a chaser. Now, set that strand up so that only every third position has a bulb; that is, if bulbs are supposed to be 2 inches apart in the display, make them 6 inches apart on this strand. Now do that again with two more strands, only having the bulbs be in one position before and one after the first.
Plug all of those into a chaser that can do what's called a \"negative chase sequence\". In that, instead of every nth light being on, every nth light is off.
Instant Pyramid lights.