I've been wondering how to compute this one for a while, and I've done some initial work but it seems to be going nowhere.

Find the probability of holding a Royal Flush in a n hand draw, where n must be atleast 5 but no greater than 52. Also, find the value of n that gives a 100% chance to draw a royal flush.

I have seen some VERY obscure stuff about this question online, but I'd like to get down to business on it!