(defn inner
  [i]
  (loop [j 1]
    (if (= 0 (rem i j))
      (if (< j 20)
        (recur (+ 1 j))
        i)
      nil)))

(defn loops
  []
  (loop [i 20]
    (let [result (inner i)]
      (if result
        (print (format "Number %d\n" result))
        (recur (+ i 20))))))

(defn time-me []
  (time (loops)))