Simple questions like 1+1 can also be fun since R1 goes overboard (as do some other models when you include a system prompt asking it to think) https://sugaku.net/qna/a1b970c0-de9f-4e62-9e03-f62c5280a311/
And if that fails you can ask for the zeros of the ΞΆ function! https://sugaku.net/qna/c64d6db9-5547-4213-acb2-53d10ed95227/