A275004 - OEIS

%I #11 Jan 11 2020 15:57:47

%S 6,10,50,4440892098500626161694526672363281250

%N a(n) = f_n(2), with f_0(x) = x+4, f_n+1(x) = (f_n)^x(x).

%C Next term is too large to include.

%C This function is a particular instance of the fast-iteration hierarchy function F[k]_n(x). Here we have f_n(x) = F[4]_n(x). See A275000 for details and definitions and formulae.

%t f[0, x_] := x + 4; f[n_, x_] := Nest[f[n - 1, # ]&, x, x]; Table[f[n, 2], {n, 0, 3}]

%Y A154714(F[1]_n(2)), A275002(F[n]_3(2)), A275003(F[3]_n(x)), A275005(F[5]_n(x)), A275006(F[6]_n(x)), A275009(F[k]_n(2)).

%K nonn

%O 0,1

%A _Natan Arie Consigli_, Nov 09 2016