(3n-3)! --------- = (3n+3)! (3n-3)! ----------------------------------------------- = ((3n-3)!)((3n-2)(3n-1)(3n)(3n+1)(3n+2)(3n+3)) 1 -------------------------------------- ((3n-2)(3n-1)(3n)(3n+1)(3n+2)(3n+3))