Response to http://www.williamcaputo.com/archives/000319.html

gistfile1.clj

(defn follow-chain [base-url number]
  (let [result (slurp (str base-url number))]
    (if-let [next-number
             (if (re-find #"^Yes" result)
               (/ (Integer/parseInt number) 2)
               (let [idx (.indexOf result "and the next")]
                 (when (>= idx 0)
                   (last (string/split (subs result idx) #" ")))))]
      (do
        (println result)
        (recur base-url next-number))
      result)))

Obviously without the println and resulting do block, this would look neater.