Distinct terms in a multiplication table

gistfile1.clj

;; Project Euler
;;
;; Problem 466
;; https://projecteuler.net/problem=466
;; Find P(64,10e16)

(defn distinct-mult [a b]
  (loop [sol #{}
         n 0
         x (range 1 (inc b))
         y (range 1 (inc a))]
    (if (seq x)
      (recur (apply conj sol (map #(* % (first x)) y))
             (inc n)
             (rest x)
             y)
      sol)))

(time
 (count (distinct-mult 32 1e3)))
;; "Elapsed time: 20.41 msecs"
;; => 13990

(time
 (count (distinct-mult 32 1e4)))
;; "Elapsed time: 385.757 msecs"
;; => 138129

(time
 (count (distinct-mult 32 1e5)))
;; "Elapsed time: 4455.01 msecs"
;; => 1382819

(time
 (count (distinct-mult 32 1e6)))
;; "Elapsed time: 79980.211 msecs"
;; => 13826337