Clojure ratios

ratios.clj

;; clojure solution for https://medium.com/@bellmar/is-cobol-holding-you-hostage-with-math-5498c0eb428b
;; HN: https://news.ycombinator.com/item?id=17636029

(defn rec [y z]
  (- 108
     (/ (- 815
           (/ 1500 z))
        y)))

(defn rec-list [N]
  (->> (iterate (fn [[x:i-2 x:i-1]]
                  [x:i-1 (rec x:i-1 x:i-2)])
                [4 17/4])
       (take N)
       (map first)
       (map double)))

;; Usage
;; =====
(rec-list 20)

;; returns

(4.0
 4.25
 4.470588235294118
 4.644736842105263
 4.770538243626062
 4.855700712589074
 4.910847499082793
 4.945537404123917
 4.966962581762701
 4.980045701355631
 4.987979448478392
 4.992770288062068
 4.995655891506634
 4.997391268381344
 4.998433943944817
 4.999060071970894
 4.999435937146839
 4.999661524103768
 4.999796900713418
 4.999878135477931)