Given a word length n and max number of consecutive vowels k ,we need to tell how many words that we can form using given constraints.

n=3 and k=2 means we have to tell the number of words of length 3 and in which we can use at most k consecutive vowels.

I know its a dynamic programming problem but unable to figure out the recurrence.Please help!

word can contain letters only 21 consonants and 5 vowels