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/p92.clj

Created October 29, 2009 03:07
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p92.clj
; Project Euler, problem 92
(use 'clojure.contrib.math)
(defn digits-of [n]
(map read-string (map str (str n))))
(defn chain [n]
(let [sum (apply + (map #(expt % 2) (digits-of n)))]
(lazy-seq
(cons n (chain sum)))))
(defn is-in? [xs n]
(some #(= % n) xs))
(println (count (filter #(is-in? (chain %) 89) (range 1 10000000)))
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