User blog comment:Googology Noob/SuperJedi's X Function/@comment-27173506-20160102103337

Here's Graham's Number:

U(a,b,1)=a^b

U(a,1,c)=a

U(a,Sb,Sc)=U(a,U(a,b,Sc),c)

G0=4

GSn=U(3,Gn,3)

G64

And Hypergraham:

U(a,b,1)=a^b

U(a,1,c)=a

U(a,Sb,Sc)=U(a,U(a,b,Sc),c)

G0=4

GSn=U(3,Gn,3)

H0=64

HSn=GHn

HG64

Anybody got better?