(Now that I think about it, choosing a Schelling point does have the disadvantage that should I win, I'd have to split the jackpot with more people, but I don't think that's ever gonna happen anyway.))

With this in mind I think I would choose combinations that match the pattern /[3-9][0-9][3-9][0-9][1-6][0-9]/. Six digit numbers look too much like dates!