Writing your own infinite series - oliyh/learning-clojure GitHub Wiki

Fibonnaci

The Fibonnaci sequence is a sequence of numbers where the nth number is calculated as the sum of the n-2th and n-1th numbers. Therefore given a sequence of two numbers we can calculate the next one.

This function returns joined sequences, where each sequence contains the next value and a lazy pointer to a function that will calculate the value afterwards.

  [1 -> [1 -> [2 -> [3 -> [5 -> [8 -> ...

(defn fib 
  ([] (fib [1 1]))
  ([s] (cons (first s) (lazy-seq (fib [(last s) (+ (first s) (last s))])))))