(defun fib (x) (if (< x 2) x (+ (fib (1- x)) (fib (- x 2))))) (defun fibi (n) (do ((i 1 (1+ i)) (fib-i-1 0 fib-i) (fib-i 1 (+ fib-i fib-i-1))) ((= i n) fib-i)))