One idea that I had was to inline the factoring logic into twice- composite. Who cares about the factors? We just want to know if there are two or not:
(defn twice-composite? [n] (loop [ps prime-seq tmp n p-count 0] (if (< 2 p-count) false (if (= 1 tmp) (= 2 p-count) (let [p (first ps)] (if (divides? tmp p) (recur ps (quot tmp p) (inc p-count)) (recur (rest ps) tmp p-count)))))) ) But this lead to even slower code. On Nov 3, 2:15 pm, Mark Engelberg <mark.engelb...@gmail.com> wrote: > Your Clojure implementation of your particular approach is reasonable, > but you need a cleverer approach. I'll send you a hint offline. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en