The question

Has anyone seen that notation before? I haven't.

Maybe it just means to the power of ???

C(9) = 27

27^m=1

m=0

I think it means you just keep putting the number you calculate back into the function until the result is 1. i.e. C(9) = 28, C(28) = 14, C(14) = 7, ...etc.

Here is a short computer program that does the calculations:

Thanks Alan