(de nmbr (N)
   (let (A 1  B 0)
      (while (gt0 N)
         (if (bit? 1 N)
            (inc 'B A)
            (inc 'A B) )
         (setq N (>> 1 N)) )
      B ) )

(let Lst (mapcar nmbr (range 1 2000))
   (println 'First-15: (head 15 Lst))
   (for N 10
      (println 'First N 'found 'at: (index N Lst)) )
   (println 'First 100 'found 'at: (index 100 Lst))
   (for (L Lst (cdr L) (cddr L))
      (test 1 (gcd (car L) (cadr L))) )
   (prinl "All consecutive pairs are relative prime!") )