As a rough (even rougher!) approximation, English syllables consist of an onset that is either one of 25 consonants or a cluster of any two of these consonants, followed by one of 16 vowels, followed...

As a rough (even rougher!) approximation, English syllables consist of an onset that is either one of 25 consonants or a cluster of any two of these consonants, followed by one of 16 vowels, followed optionally by one of 25 consonants. How many English syllables are there?