I noticed for one of the largest communities, there was no icon! It looks strange in the Communities view. Anyways, I mocked these up trying to use the Lemmy logo. If you like any of them but it’s not quite right, I can adjust it - or if you have a new idea, I’m down to try that too!
5 is my favorite. 5 > 4. 2/3 would be great with a circle at the bottom of the question mark. 1 just looks weird to me.