Turning the number of countries into a power of two is doable: add all countries and the least shitty territories.

Turning the number of nationalities is harder. After you’ve added all current nationalities, added all regions, shrugged and added Soviet and Yogoslavian and the like, extended the scope a bit to also add Lunarian, Martian, Solarian, and Andromedean, then extended a bit more and added Narnian and Klingon, really, REALLY stretched it and added Vegetarian and Vegan, I’m still 38 short of 256…