My first Racket program: functional implementation of the hyperoperators

hyperop.rkt

#lang racket
(require racket/match)

; https://en.wikipedia.org/wiki/Hyperoperation#Definition
; Because the base case is succession, it becomes unusable at tetration.
(define (hyperoperator-succ n a b)
  (match (list n a b)
    [(list 0 _ _) (+ b 1)]
    [(list 1 _ 0) a]
    [(list 2 _ 0) 0]
    [(list n _ 0) #:when (>= n 3) 1]
    [_ (hyperoperator (- n 1) a (hyperoperator n a (- b 1)))]
  )
)

; Add more speedy base cases
(define (hyperoperator n a b)
  (match (list n a b)
    [(list 0 _ _) (+ b 1)]
    [(list 1 _ _) (+ a b)]
    [(list 2 _ _) (* a b)]
    [(list 3 _ _) (expt a b)]
    [(list n _ 0) #:when (> n 3) 1]
    [_ (hyperoperator (- n 1) a (hyperoperator n a (- b 1)))]
  )
)

(define (H n) (lambda (a b) (hyperoperator n a b)))