Good game. I had a programming teacher that was obsessed with the Fibonacci sequence, so for better or worse I think of him every time I see the word.
Took me a while to figure out how the numbers were actually coming out though, like which tiles were used in the calculation.
If you want to continue to polish this, maybe offering a tutorial round that shows you how numbers are calculated would make this great.
I was thinking maybe just by hovering over a tile, it would show you what tiles would be placed when you clicked.
This seems like it'd be great on mobile, not sure how the hover tutorial would work on mobile, but I'm sure you got it! :)