(define (random-numbers stream)
  (define (next-rand seed stream)
    (cond
      [(eq? (stream-car stream) 'generate)
       (cons-stream seed (next-rand (+ seed 1) (stream-cdr stream)))]
      [else (cons-stream (stream-car stream) (next-rand (stream-car stream) (stream-cdr stream)))]))
  (next-rand 0 stream))