(defn fibs [a b] (cons a (lazy-seq (fibs b (+' a b)))))

(defn fizzbuzz [x]
  (condp #(zero? (mod %2 %1)) x
    15 "FizzBuzz"
     5 "Buzz"
     3 "Fizz"
       x))

(def fibbuzz-seq (map fizzbuzz (fibs 1 1)))

; (take 100 fibbuzz-seq)
; -> (1 1 2 "Fizz" "Buzz" 8 13 "Fizz" ... 218922995834555169026N "FizzBuzz")