> x=3 while 1 do x=math.log(C,x)print(x)end
34 chars: ::B::X=math.log(C,X)print(X)goto B
I acknowledge Dirk's idea for using math.log in an unorthodox way with a variable base. Endless printing using goto was my own idea before the endless printing was explicitly stipulated by Egor. The final guess to use uninitialised X was my own.
Cheers,
V.