I can see how this would be easy if you thought of a certain way of doing it off the bat, but as someone who did not, it was quite frustrating lol. Good challenge though

This kata is old and has been solved many times. Its design won't be changed since it would invalidate all submitted solutions.

bruh. input validation in an 8 kyu? not to mention it's uneccessarily confusing with the different results expected for positives and negatives. maybe look into changing those things

Probably because you had to come up with an equation that represents the series.
I have not run into that too much but I am comfortable doing that. They prob.
should of gave the equation. Not here to learn about math although kind of
a prequesite for programming in general.

fine, a 'series of numbers' if you prefer. As someoone who is firmly in the 7th kyu category, I feel pretty qualified to say this felt significantly harder than the previous katas I've done.

Except you don't need an array at all. You need a loop and some formatting, that doesn't seem to be higher than 7 kyu IMO.