lychrel->>.clj

(defn reverse-int
  "Returns an integer with its digits reversed, e.g. 123 returns 321"
  [x]
  (BigInteger. (su/reverse (pr-str x))))

(defn palindromic?
  "Returns true if the number is palindromic, e.g. 121, 1234321"
  [x]
  (= x (reverse-int x)))

(defn lychrel?
  ([x] (lychrel? x 50))
  ([x iterations]
     (let [next-num #(+ % (reverse-int %))]
       (->> x
            (iterate next-num)
            rest
            (take iterations)
            (some palindromic?)
            not))))