Some examples of how to get the 15 first fibonacci numbers in Clojure

fibonacci.clj

; Classic recursion
(defn fibo [n]
  (if (or (= n 0) (= n 1))
    n
    (+ (fibo (dec n)) (fibo (- n 2)))))

(map fibo (range 15))

; Tail-call recursion
(defn fibo2 [n]
  (loop [cnt n fst 0 scd 1]
    (if (zero? cnt)
      fst
      (recur (dec cnt) scd (+ fst scd)))))

(map fibo2 (range 15))

; Lazy sequence
(defn fibo3 [fst scd]
  (lazy-seq (cons fst (fibo3 scd (+ fst scd)))))

(take 15 (fibo3 0 1))

; Haskell's zipWith inspired oneliner solution
(def fibo4 (lazy-cat [0 1] (map + fibo4 (rest fibo4))))

(take 15 fibo4)