I do have a janky random-access rng algo that
looks
random, but it obviously isn't. May be close enough for my needs.
http://platitudinous.net/dungeon/rng
Basically double-seeded, with some goofy division and exponents going on, then multiply by pi and truncate the whole-number part.
I can't get to the code right now, but I'll post the important part this evening.