(defun scale (end step &optional current)
  (unless current (setq current 0))
  (if (<= current end)
      (let*((digit-str (if (= (% current step) 0) (format "%s" current) "."))
            (digit-str-len  (length digit-str)) )
        (insert digit-str)
        (scale end step (+ digit-str-len current)) )))

(defun scale-simple (&optional end)
  (interactive "p")
  (let*((the-end  (if (= end 1) 30 end))
        (the-step (max 1 (/ the-end 10))) )
    (scale the-end the-step) ))

;; C-u       M-x scale-simple RET        01234
;; C-u C-u   M-x scale-simple RET        012345678910121416
;;           M-x scale-simple RET        0..3..6..9..12.15.18.21.24.27.30
;; C-u 1 0 0 M-x scale-simple RET        0.........10........20........30 ...