User blog comment:Kyodaisuu/English description of Fish numbers/@comment-10429372-20131102144937/@comment-24061664-20131102153025

BB1(n) uses BB0(n) (normal busy beaver function) as an oracle, and BBn(n) uses BBn-1(n) uses as an oracle, is it correct? If so, it can be evaluated with busy beaver hierarchy, explained in the calulation of F4 section, as

B0(n) = B[1] B1<n) = B[2] Bi(n) = B[i+1] Bn(n) = B[&omega;]

F4(n) = B[&omega;&omega+1 &times; 63] is larger than this.