binconv.clj

(defn pow2 [n]
  "Returns a long representing 2^n"
  (->> n (Math/pow 2) long))

(defn b10->b2
  "Converts a base 10 number to a lazy seq of 1's and 0's that make up a base 2 number"
  ([n] (b10->b2 n '()))
  ([n col]
   (if (= 1 n)
     (merge col 1) ; base case
     (let [r (mod n 2)]
       (b10->b2 (->> (/ n 2) Math/floor long) (merge col r))))))

(defn b2->b10 [col]
  "Converts a seq of 1's and 0's that make up a base 2 number into a base 10 number"
  (when (seq col)
    (reduce + (map #(if (zero? (second %)) 0 (pow2 (first %))) (map-indexed vector (reverse col))))))