0,1

Next term is too large to include.

This function is a particular instance of the fast-iteration hierarchy function F[k]_n(x). Here we have f_n(x) = F[2]_n(x). See A275000 for details and definitions and formulae.

Table of n, a(n) for n=0..3.

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

Cf. A275000(F[n]_n(x)), A154714 (F[1]_n(x)).

Sequence in context: A005959 A057393 A196570 * A317584 A012928 A013160

Adjacent sequences: A274989 A274990 A274991 * A274993 A274994 A274995

nonn

Natan Arie' Consigli, Oct 08 2016

approved