One stone alive in seki

Seki  

Gernotti: Correct me if I'm wrong, but aren't all 16+1 white stones alive in seki? Those and the 6 black ones?

DougRidgway: They are all alive, but are they the same group? This position is intended as a counterexample to my claim that two stones alive in seki was the smallest living group. Since all of these positions involve seki, none of the groups are independent, so it's not exactly clear what "smallest" means.

Alex Weldon: Simpler than this is just a single stone in the middle of a butterfly seven which is alive in seki.

Tim Hunt: See also Hanezeki.

Karl Knechtel: And also cutting seki.