Using prediction error as the definition of curiosity rings hollow for me. Curiosity in my mind is more about mapping out an unexplored thing and not about being surprised.
If you're not surprised at any point in mapping out an unexplored thing, in what sense is it unexplored?
There are pretty high odds you've never been to this exact page before: https://oeis.org/A000079. But once you click on it, is there any remaining curiosity? It's an unexplored thing, in the sense that (I presume) you've never looked at this exact page before. But it doesn't provoke curiousity because there's nothing there to surprise you.