The "first" link (after the home button) on bbchallenge is the header bar link to https://bbchallenge.org/story which cites Aaronson in the first sentence (double first!). I would not describe it like OP for someone trying to find the actual link ;)
"One Collatz Coincidence", the 2nd story on the blog, also mentions Aaronson
"One Collatz Coincidence", the 2nd story on the blog, also mentions Aaronson