You wanted a prize! LOL. Well, as the original prize was a cut of the post profits, then converted to new model steem is probably worth a few cents ;-)
However, worth the effort and interest. Let me offer you either 1 MAPR token or 1 MAXUV token, both worth about 1 STEEM (even after HF21). Let me know which you prefer.
BTW, your solution is correct, and can be found here on OEIS, one of those amazing internet niche resources.
RE: Brainsteem Compute #3 Prize Computational Maths Puzzle [Win 40% and 10% in SBD]