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 A347058 #13 Aug 03 2024 12:40:19
%S A347058 9,9,8,1,3,6,0,3,8,1,1,0,3,7,4,9,7,2,1,3,2,3,4,5,2,9,0,0,0,6,2,6,8,3,
%T A347058 5,5,9,4,8,4,4,9,5,9,5,4,0,2,2,9,3,8,0,7,1,8,1,3,0,6,2,0,7,9,8,9,2,7,
%U A347058 0,6,4,9,4,9,1,4,1,0,8,5,8,8,4,2,6,4,1
%N A347058 Decimal expansion of (1 + tanh(Pi)) / 2.
%H A347058 L. B. W. Jolley, <a href="https://archive.org/details/summationofserie00joll">Summation of Series</a>, Dover, 1961, Eq. (944).
%H A347058 Michael I. Shamos, <a href="https://citeseerx.ist.psu.edu/pdf/ae33a269baba5e8b1038e719fb3209e8a00abec5">Shamos's catalog of the real numbers</a> (2011).
%F A347058 Equals exp(2*Pi) / (1 + exp(2*Pi)).
%F A347058 Equals Sum_{k>=0} (-1)^k * exp(-2*Pi*k).
%e A347058 0.99813603811037497213234529000626835594844959540...
%t A347058 RealDigits[(1 + Tanh[Pi])/2, 10, 120][[1]] (* _Amiram Eldar_, Jun 07 2023 *)
%Y A347058 Cf. A216707, A344505.
%K A347058 nonn,cons
%O A347058 0,1
%A A347058 _Sean A. Irvine_, Aug 14 2021