The trouble with that is the fact that there are some N numbers no longer on record.
I found this out while researching a 63 172 I was looking at. Looked up the N number, and came up with a blank page, "N number does not exist".
Called the FAA, and found out that after the re-registration thing started, any aircraft not re-registered, loses it's n number,(after a period of time) and so nothing shows up on the search. But, when searched by serial number, you get all the info you would ever want, along with the fact that it had not been re-upped on registration.
This particular aircraft had not been registered for 3 registration cycles, and is sitting derelict on the ramp. Performing an N number search will turn up nothing on this airplane.