Steps in

steps.clj

(defn from-to
  "For two integers create a sequence [a, a+x, ..., b, b) where x may be 1 or -1"
  [a b]
  (let [step (if (pos? (- a b)) -1 1)]
    (concat (range a b step) (repeat b))))

(defn from-to-seq
  [x y]
  (let [max-distance (->> (map - x y) (map #(Math/abs %)) (apply max))]
    (->> (map from-to x y)
         (map (partial take max-distance))
         (apply map vector))))