title: Scheme (Lazy Racket) an infinite list of natural numbers
body: <p>I think that <a href="http://docs.racket-lang.org/lazy/" rel="nofollow">Lazy Racket</a> should be useful for handling infinite lists. According to the <a href="http://en.wikipedia.org/wiki/Racket_features#Lazy_Racket" rel="nofollow">Wikipedia Lazy Racket article</a>, <code>fibs</code> (the infinite list of Fibonacci numbers) can be defined as:</p>
  
  <pre><code>;; An infinite list:
  (define fibs (list* 1 1 (map + fibs (cdr fibs))))
  </code></pre>
  
  <p>How do we define an infinite list of natural numbers?</p>