gistfile1.lisp

(defn euler5 []
  (+ 1
   (last
    (take-while (fn [w] (not 
                         (every? #(zero? (rem w %)) (range 1 20) )))
                        (range 1 1000000000000 1)))))

;; Takes about 5 mins on my machine
(defn euler5b []
  (first (drop-while
     (fn [n] (not (every? #(zero? (rem n %)) (range 1 21))))
     (iterate inc 1))))

;; Takes about 10 seconds
(defn euler5c []
  (first
    (drop-while
      (fn [n] (not (every? #(zero? (rem n %)) (range 10 20))))
      (iterate #(+ 20 %) 20))))