I'm looking for a particular tool I once came across. It took a decimal number as input and tried to give some calculation which would return that number as the result. I'm familiar with Plouffe's Inverter and its old form, the Inverse Symbolic Calculator, but neither of these is the tool I'm looking for. These tools are essentially lookups on large tables; the one I remember was a program that found increasingly-complex representations of the number that more closely aproximated it. Plouffe's tools are online; this one was downloadable (a console application, with source code I think). The documentation, such as it was, mentioned the ISC and explained how the two were different. Does anyone know what I'm talking about? Failing that, does anyone know of something similar?