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 A242070 #13 Jan 17 2020 05:43:37
%S A242070 2,8,1,3,0,1,4,0,2,0,2,5,2,8,9,8,3,6,7,5,2,7,2,5,5,4,0,1,2,1,6,6,8,6,
%T A242070 9,6,3,8,4,6,1,4,0,5,6,0,5,4,0,2,6,2,2,1,5,2,6,6,4,3,8,7,4,0,4,7,1,5,
%U A242070 0,8,3,6,8,9,2,3,7,0,7,9,9,5,8,4,0,2,0,7,1,8,2,6,3,6,9,6,0,5,4,1
%N A242070 Decimal expansion of the supremum of all real s such that zeta'(s+i*t) = 0 for some real t.
%H A242070 J. Arias de Reyna, J. van de Lune, <a href="http://arxiv.org/abs/1107.5134">Some bounds and limits in the theory of Riemann's zeta function.</a> arXiv:1107.5134 [math.NT]
%H A242070 Steven R. Finch, <a href="http://arxiv.org/abs/2001.00578">Errata and Addenda to Mathematical Constants.</a> p. 28.
%F A242070 The unique solution y > 1 of the equation zeta'(y)/zeta(y) = -2^(y + 1)*log(2)/(4^y - 1).
%e A242070 2.81301402025289836752725540121668696384614056054026221526643874...
%t A242070 y /. FindRoot[Zeta'[y]/Zeta[y] == -2^(y + 1)*Log[2]/(4^y - 1), {y, 2}, WorkingPrecision -> 100] // RealDigits // First
%Y A242070 Cf. A242069.
%K A242070 nonn,cons,easy
%O A242070 1,1
%A A242070 _Jean-François Alcover_, Aug 14 2014