SICP in Clojure: Chapter 1, Exercise 22

This is my Clojure solution to Chapter 1, Exercise 22:

(ns sicp.ch1.ex22

  (:require [sicp.ch1.ex21 :as sicp-ch1-ex21]))

(defn prime?

  [n]

  (= n (sicp-ch1-ex21/smallest-divisor n)))

(defn report-prime

  [n elapsed-time]

  (println "* " n elapsed-time))

(defn runtime

  []

  (System/nanoTime))

(defn start-prime-test

  [n start-time]

  (let [p (prime? n)]

    (when p

      (report-prime n (- (runtime) start-time)))

    p))

(defn timed-prime-test

  [n]

  (start-prime-test n (runtime)))

(defn search-for-primes

  [start cnt]

  (reduce

   (fn [acc x]

     (if (= cnt (count acc))

       (reduced acc)

       (if (timed-prime-test x)

         (conj acc x)

         acc)))

   []

   (filter #(= 1 (rem % 2))

           (iterate inc start))))

(search-for-primes 1000 3) ; ~5,000ns

(search-for-primes 10000 3) ; ~15,000ns

(search-for-primes 100000 3) ; ~50,000ns

(search-for-primes 1000000 3) ; ~160,000ns