Sudoku Box

(define top 6)
(define left 3)

(flatten
   (build-list 3
               (lambda (n)
                 (build-list 3
                             (lambda (m)
                               (+ (* 27 (/ top 3)) (* left 3) (* 9 m) n)
                               )))))
'(63 72 81 64 73 82 65 74 83)