This is the closest to it I believe. When Naruto was learning the Rasengan Jiraiya told him that he didn't even need to learn the (complicated) hand seals.
Originally Posted by 000_
So that means either: A) Rasengan has handseals, but does not require them or B) I read a wonky translation that skewed the naunces of the conversation.
In either case, I think that handseals just simplify the process to make it easier to use things, but it doesn't have that many options as all the seals correspond to the Chinese Zodiac. (At least from what I've seen.)
An interesting note is that some seem to have extraordinarily long combinations. If you look at the battle between Kakashi and Zabuza, when Kakashi copies that big water explosion thing it shows over 100 handseals behind the text. This leads me to believe Jiraiya taught Naruto Rasengan with no handseals because it would be so complicated that Naruto would have no chance of remembering it, as he is an idiot.
"Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn."