This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A218583 #20 Apr 25 2025 20:39:08
%S A218583 0,6,1,3,3,1,2,4,2,3,0,0,0,8,3,5,1,2,3,4,3,9,8,5,5,9,9,6,9,5,0,0,6,0,
%T A218583 4,5,0,6,1,2,1,0,2,6,4,5,2,8,7,7,9,7,3,3,6,4,2,5,7,5,2,0,6,6,3,4,7,8,
%U A218583 1,6,6,9,5,6,2,0,2,8,9,4,7,0,1,6,5,1,8,3,8,9,2,5,7,9,7,4,4,8,2
%N A218583 Decimal expansion of the limit of the n-fold application of the natural logarithm to A049384 as n tends to infinity.
%C A218583 The value can be calculated to an accuracy of at least 4.8*10^183230 decimal digits by calculating log(...log(7^...^1)...).
%H A218583 <a href="http://math.stackexchange.com/questions/216937/limit-of-log-log-logn-n-1">Proof that the series converges</a> (StackExchange, 10/09/2012)
%F A218583 Equals -log(...log(n^(n-1)^...^1)...) (n nested log).
%e A218583 -0.0613312423000835123439855996950060450612102645287...
%t A218583 p[n_] := HoldForm[n]^(p[n - 1]); p[1] := 1; rules = {Log[x_ y_] :> Log[x] + Log[y], Log[x_^k_] :> k Log[x]}; lnn[x_, n_] := Log[lnn[x, n - 1]]; lnn[x_, 0] := x; RealDigits[ReleaseHold[lnn[p[7], 7] //. rules], 10, 100, 0]
%Y A218583 Cf. A049384.
%K A218583 nonn,cons
%O A218583 0,2
%A A218583 _Benedikt Otten_, Nov 03 2012