Fibonacci calculator

Probably not very useful for audio, but perhaps of interest for some. Here’s a simple Fibonacci number calculator that can be run in the Nyquist Prompt effect.
Q. Why is the maximum value of “n” 46?
A. Because Nyquist calculates using 32-bit numbers and the 47th term of the Fibonacci series is 2971215073, which is too big for a 32-bit signed integer.

;control n "Fibonacci (n)" int "" 0 0 46

(defun fib (n)
  (case n
    ((0 1) n)
    (t (let ((fib-2 0)
             (fib-1 1))
        (dotimes (i (1- n) fib)
          (setf fib (+ fib-2 fib-1))
          (psetq fib-2 fib-1
                 fib-1 fib))))))

(format nil
  "The ~a~a term of the Fibonacci series is: ~a"
  (case n (1 "st")(2 "nd")(3 "rd")(t "th"))
  (fib n))