[math-fun] I just saw CA plate XKCD793.

Puzzle: It was orange on black. Seven letter vanities ("environmentals") were not introduced until decades after the switch to orange on blue. I distinctly remember an episode of Columbo where the perp had orange on blue CARSINI, a safe bet for the writers, before seven letters were legal. --rwg If I see XKCD1047, I'll know it's a fake. (Note the rollover warning about πᵗʰ root.) WRI support just told me the secret way to get Mma to display πᵗʰ root of 4. (http://www.tweedledum.com/rwg/idents.htm)