The OP was talking about the 13" MBP and not the MacBook Pro with Retina Display, thus the maximum external resolution is 2560 x 1600, unless you are able to hack that integrated graphics processor (IGP), as that is the limit Apple put in to drive a 30" display at maximum (I am not talking about HDTVs here).
I don't know what you mean with 16384 x 16384 though, as that is 268 MegaPixel, and I don't know of any video card being able to drive that available on the free market.