I tried punching in 243 and it gave me an equation that resolves to 235.
Tried it a few other times and it seems to sometimes like giving something that results in 3^5 (which would be 243 on its own) followed by subtracting a bit from it, which ends up making it the wrong answer. In the link above, it basically goes (3^5) - (8 - (1 - 1)), so if you only keep the first brackets it would be correct.
I'm personally skipping because I already have what I'd want from this one, but I will say P4G is my favorite of the Persona series, and one of the few long JRPGs I've actually finished in the last several years. (P5R is also great, but 4's more grounded story and characters, relatively speaking, give it the edge for me.)
And Cassette Beasts is a truly great Pokemon-like that has so much going for it. If you feel out of love with the Pokemon franchise, or if you still enjoy it but would want more, this is a really fun game with its own take on a lot of the mechanics. Lots of depth combined with customizable difficulty.