badgenome on 03 July 2009
That's odd. There always seem to be places where I can count on fighting some Raiders or mutants again a few days (or maybe a week) after I last killed them.
It does seem to change from game to game, though. My first couple of games, I would always see Raiders around the supermarket, but they don't spawn there in my current game.
You might want to try under the bridge near the Citadel, or the apartments behind the library. There are usually Raiders around there.
