(defun print-n (n c)
  (let ((i 0))
  (while (< i n)
    (princ c)
    (setq i (+ i 1)))))

(defun pyramid (n)
  (let ((indent-level (- n 1))
        (width 1))
    (while (>= indent-level 0)
      (print-n indent-level " ")
      (print-n width "*")
      (princ "\n")
      (setq indent-level (- indent-level 1))
      (setq width (+ width 2)))))