Re: What episode is the most unreferenced?
Hm, not sure how much it counts but both SCE Ishtar Rising (1 and 2) and A Time to Sow mention Seyetik... Just looked it up.
First one just says his hologram was used. Second has Geordi familiar with his terraforming work.
I don't like bullies, I don't like threats, and I don't like you! - Janeway, "State of Flux"