Lisp

Like many others, I read Paul Graham's Lisp essays and thought I should give Lisp a go. I installed Clojure and wrote my first Lisp program: 

(defn num_books
 ([dist]
   (num_books dist 0 0))
 ([dist achieved nbooks]
 (if
   (>= achieved dist)
   nbooks
   (num_books dist
       (+ achieved
           (/ 1
               (+ nbooks 2)))
       (+ nbooks 1)))))

(println (num_books 1.5))

If you put a book on the edge of a table you can balance it so that it sticks out half a book length. Place another judiciously on top and it'll stick out 1/2 + 1/3 book lengths. You give the function above a number of book lengths you want the stack to stick out, and it'll return the number of books you need.

Coming from a Python background, wouldn't it make sense to use whitespace instead of parentheses? 

defn num_books
[dist]
num_books dist 0 0
[dist achieved nbooks]
if
   >= achieved dist
   nbooks
   num_books dist
       + achieved
           / 1
               + nbooks 2
       + nbooks 1

println
num_books desired_distance

Also, I'm interested to compare this function with its Python equivalent: 

def num_books(desired):
achieved = 0
nbooks = 0
while achieved < desired:
 achieved = achieved + 1 / (nbooks + 2)
 nbooks = nbooks + 1
return nbooks

The Python one is shorter, how can this be? Okay a re-write of the Lisp version: 

(defn num_books
    ([dist]
        (loop [nbooks 0 achieved 0]
          (if
              (< achieved dist)
            (recur
                (inc nbooks)
                (+ achieved
                    (/ 1
                        (+ nbooks 2))))
                nbooks))))

Python 166 chars, Lisp 186 characters. What am I doing wrong?