Project Euler Problem 7

Problem7.clj

;;; By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
;;; What is the 10 001st prime number?

(defn primes [n] (primes- '(2) (take (dec n) (iterate inc 2))))
(defn primes- [prime-list search-list]
  (let [prime-list-max (first prime-list)
        search-list-max (apply max search-list)
        search-list-next (filter #(not (zero? (mod % prime-list-max))) search-list)]
    (if (< search-list-max (* prime-list-max prime-list-max))
      (sort (concat prime-list search-list-next))
      (primes- (conj prime-list (first search-list-next)) search-list-next))))
(def primes-1000000 (primes 1000000))
(count primes-1000000)
;;;=>78498
(take 1 (drop 10000 primes-1000000))