Heh, even Larry Wall says "no, that way lies madness"

(now I want to see it in an esolang precisely because he said that)

I thought about that. I thought the compiler could error with "Insufficient data for meaningful answer" until you'd added enough digits that the sequence was unambiguous.

Then I tried it in OEIS and as you say there are too many sequences that start [1,2,3,4,5,...] - I think we may be stuck with generators and yield. But they're not exactly delightful.

That would lead to weird behavior since the OEIS is sorted by number of references, which I think prefers "interesting" solutions over straightforward ones. For (1, 2, 3), the positive integers are only ranked 5th -- the top hit are the Fibonacci numbers. It's funny to think about.

There's must be one or two for either Python or Perl. Well: https://github.com/sidneycadot/oeis