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 A274992 a(n) = f_n(2), with f_0(x) = x+2, f_n+1(x) = (f_n)^x(x). 0
 4, 6, 18, 6973568802 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS 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_n(x). See A275000 for details and definitions and formulae. LINKS Table of n, a(n) for n=0..3. MATHEMATICA f[0, x_] := x + 2; f[n_, x_] := Nest[f[n - 1, # ]&, x, x]; Table[f[n, 2], {n, 0, 3}] CROSSREFS Cf. A275000(F[n]_n(x)), A154714 (F_n(x)). Sequence in context: A005959 A057393 A196570 * A317584 A012928 A013160 Adjacent sequences: A274989 A274990 A274991 * A274993 A274994 A274995 KEYWORD nonn AUTHOR Natan Arie Consigli, Oct 08 2016 STATUS approved

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Last modified October 1 18:47 EDT 2023. Contains 365828 sequences. (Running on oeis4.)