Experimenting with lazy sequences

Fibonacci

source

(def fib-seq
     (lazy-cat [0 1] (map + (rest fib-seq) fib-seq)))

Powers of two

(def twopowers (lazy-seq (cons 1N (map #(* 2N %) twopowers))))

Factorial

(def fact (lazy-cat [1N] (map * (map #(+ % 2) (range)) fact)))