(defn next-triangle [triangle]
(let [triangle (vec (map (fn[row-string] (str " " row-string)) triangle))
triangle (assoc triangle (count triangle)
(nth (iterate (fn[row] (str row "\u25B2\u00A0")) "") (+ 1 (count triangle))))]
triangle))
(defn print-triangle [triangle]
(doall (map println triangle))
(println))
(doall (map print-triangle (take 10 (iterate next-triangle []))))
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