True. I'll update above regarding n. However, it's certainly different to the other examples and I would expect fib(2) to be 1 + 0 not 1 + 1. It's a very mino

True. I'll update above regarding n. However, it's certainly different to the other examples and I would expect fib(2) to be 1 + 0 not 1 + 1. It's a very minor point though - I think I'll stop now ;)