utopian-tree.clj

(defn calc-height-step [height current-step]
  (if (= 1 (mod current-step 2))
    (* height 2)
    (+ height 1)))

(defn calc-height []
  (def steps (Integer/parseInt (read-line)))
  (println (reduce calc-height-step 1 (range 1 (+ steps 1)))))

(def t (Integer/parseInt (read-line)))
(dotimes [n t] (calc-height))

It is highly preferred to avoid def inside a defn - use a let!

(let [steps (Integer/parseInt (read-line))]
  (println (reduce calc-height-step 1 (range 1 (+ steps 1)))))

Nice job!