Problem Statement

An   emirp   (prime spelled backwards)   are primes that when reversed   (in their decimal representation)   are a different prime. (This rules out palindromic primes.)

In each list, the numbers should be in order. Invoke the (same) program once per task requirement, this will show what limit is used as the upper bound for calculating surplus (regular) primes. The specific method of how to determine if a range or if specific values are to be shown will be left to the programmer.

Let's start with the solution:

(defn emirp? [v]
  (let [a (biginteger v)
        b (biginteger (clojure.string/reverse (str v)))]
    (and (not= a b)
         (.isProbablePrime a 16)
         (.isProbablePrime b 16))))

; Generate the output
(println "first20:    " (clojure.string/join " " (take 20 (filter emirp? (iterate inc 0)))))
(println "7700-8000:  " (clojure.string/join " " (filter emirp? (range 7700 8000))))
(println "10,000:     " (nth (filter emirp? (iterate inc 0)) 9999))