ðiːz smˈɔːlɚ sʌmˈeɪʃənz ɑːɹ nˈaʊ ɛɡzˈæktli dˌiːˌɛftˈiːz ʌv lˈɛŋθ ˈɛn slˈæʃ tˈuː ænd ˈɛn slˈæʃ fˈoːɹ, wˌɪtʃ kæn biː pɚfˈɔːɹmd ɹᵻkˈɜːsɪvli ænd ðˈɛn ɹˌiːkəmbˈaɪnd.
These smaller summations are now exactly DFTs of length N/2 and N/4, which can be performed recursively and then recombined.