I always play the (2n+1) game myself. (Or do I??)
2n for me, probably
Better than the 3n+1 game[1]. That one can really get you.
[1] https://www.quantamagazine.org/why-mathematicians-still-cant...
That's what they... er, you... er, somebody wants you to think?
That’s my secret… I never think.