Determine whether there exists a string of the alphabet in which every sequence of length 3 occurs exactly once, except for sequences of the form vowel-consonant-vowel and consonant-vowel-consonant.
Would commenting that the formula found here - http://en.wikipedia.org/wiki/De_Bruijn_sequence - be enough to argue that a De Bruijn sequence exists? I am only asking because this seems like far too easy of a question if that is so.
If I am wrong, any nudges to the right direction would be greatly appreciated. Thanks!