 Similarly, this same argument shows that when formula_32 is even, formula_103 will be even.Equation (15) shows that if formula_103 is even, formula_37 is an integer multiple of formula_41.Therefore, formula_36 is defined for formula_32 even, and is thus the proper index to use when n is even, and similarly formula_111 is defined for formula_32 odd, making it the proper index in this latter case.