Here's a number that's very large. The way it works is similar to the Goodstein Sequence, except things are expressed in hypernomials. [[0,0,0],[0,0,[0,0,0]],[0,0,[0,0,0]]]=[1,2,2] already reaches C(0) in the catching hierarchy, or pi(W) in pi notation. [C(0),2,2] reaches pi(W*pi(W)) in pi notation. The limit of this notation is pi(W^2)
This method seems very unusual, so it may be hard to analyze.
