von Neumann Integer Generator
With this on-line tool you can generate a certain von Neumann integer. Just type the integer you want to see as sequence of braces and hit the button.
The von Neumann integer grows exponentially, for N>0 it has 5*2N-1-1 characters. Therefore there is a limit for this generator: 15 is the greatest natural number for which will be generated the corresponding von Neumann integer.