(defn doors [] (reduce (fn [doors idx] (assoc doors idx true)) (into [] (repeat 100 false)) (map #(dec (* % %)) (range 1 11)))) (defn open-doors [] (for [[d n] (map vector (doors) (iterate inc 1)) :when d] n)) (defn print-open-doors [] (println "Open doors after 100 passes:" (apply str (interpose ", " (open-doors)))))