User blog comment:Alejandro Magno/My -illion is bigger!/@comment-4297047-20140923191653/@comment-25371339-20140923192907

Let H**(n,0) equal H**(n,0), H**(n,m+1) equal HH**(n,m)(n), H**(a,b,…,c,1) equal H**(a,b,…,c), and H**(a,…,b,c,d) equal H**(a,…,b,H**(a,…b,c,d-1)).

Hyperhypterillion=H**(10,10,10,10).