Discovering Map function in clojure

Here it's the simple function in clojure using map

(map + [1 2 3] [4 5 6] [7 8 9]) 

then it returns

=> [12 15 18] It's nice an simple ;-)

My first function in clojure

This a simple recursive countdown, but in clojure is more interesting. This is the code:

(defn countdown [x]
 (if (zero? x)
  (do 
   :blastoff!
   (println "Zero")
  )
  (do
   (println x)
   (recur (dec x))
  )
 ) 
)