A-M baby

Task/Happy-numbers/Clojure/happy-numbers.clj

@@ -0,0 +1,14 @@
+(defn- digit-to-num [d] (Character/digit d 10))
+(defn- square [n] (* n n))
+
+(defn happy? [n]
+  (loop [n n, seen #{}]
+    (cond (= n 1)  true
+          (seen n) false
+          :else
+          (recur (reduce + (map (comp square digit-to-num) (str n)))
+                 (conj seen n)))))
+
+(def happy-numbers (filter happy? (iterate inc 1)))
+
+(println (take 8 happy-numbers))