jneira-4clojure-solution67.clj

;; jneira's solution to http://4clojure.com/problem/67

(fn primes3 [n]
  (let
      [next-prime
       (fn [prs]
         (letfn
             [(aux [[f & r :as c] nxt]
                   (println c nxt)
                   (cond
                    (empty? c) (conj prs nxt)
                    (zero? (mod nxt f)) (recur prs (inc nxt))
                    :else (recur (take-while #(< % (quot nxt f)) r)
                                 nxt)))]
           (aux prs (inc (last prs)))))]
    (->> (iterate next-prime [2])
         (take n)
         (last))))