Thomson's Lamp! Warning: It glitches. Use Turbo Mode and SmallScreen. I did not expect it to work on Scratch, But I thought it would be cool. If you want to see it again, PRESS THE GREEN FLAG THEN BEGIN! DO NOT PRESS BEGIN AGAIN! I'm sure it is not accurate, but as stated above, I think it's neat. It glitches heavily, and Turbo Mode seems to work the best, though it does not always stop at 120. You have to wait 60 seconds for stuff to start changing, 105 to stop having to wait a while, and 116 for stuff to get weird.
I don't want to copy and paste what the Lamp is, so go Google it. VSauce made a video on it called Supertasks. And the answer is Even! Of course, this is only according to a coding program that deals with catformers, not infinite activities in a finite interval. There is no last number. We should know. Humans pretty much invented numbers. Also, it might have stopped at on, but it is difficult to tell. My guess is on off, for the program started at on, and for a chain the first and last must alternate.