euler21.clj

(defn proper-devisors [n]
     (filter #(= (rem n %) 0) (range 1 (inc (quot n 2)))))

(defn d [n]
    (reduce + (proper-devisors n)))

(defn amicable? [n]
    (let [dn (d n)
          ddn (d dn) ]
          (and (= n ddn) (not (= n dn)))))

(defn p21 []
    (reduce + (filter amicable? (range 1 10000))))

(p21)