>This problem is accessible to anyone who knows basic high school algebra

Are you sure? Spotting the pattern isn't easy and I imagine a lot of high schoolers would give up in frustration while going down wrong roads. A good portion probably wouldn't even write down the numbers without errors. And even if you get past that, most high schoolers don't know how to do/write proofs. I'd be shocked if more than 10% could actually complete all your steps.

With challenging problem solving like that I'm afraid you're going to breed a lot of resentment.