Statistics about the powers of two

powow.clj

(defn powow
  [n]
  (let [
    exp (fn exp [x n] (reduce * (repeat n x)))
    pow (str (exp 2N n))
    len (count pow) 
    sum (reduce 
      (fn
        [sum x]
        (+ sum (- (int x) (int \0))))
      0
      pow)]
    (vector pow sum len (/ sum len 1.0))))
(powow 100)