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 A336003 #4 Jul 08 2020 08:08:21
%S A336003 5,8,9,7,5,5,2,1,5,8,4,0,2,9,0,1,5,7,5,3,5,9,6,1,7,5,9,6,8,0,1,9,4,6,
%T A336003 2,8,3,0,3,2,4,4,5,6,4,0,4,1,1,5,9,6,8,4,6,5,6,7,6,0,3,2,6,6,5,4,6,0,
%U A336003 4,3,0,2,3,1,3,0,5,6,7,3,4,9,9,3,3,0
%N A336003 Decimal expansion of the number u such that the arclength on y = e^x from (0,1) to (u, e^u) is 1.
%e A336003 u = 0.5897552158402901575359617596...
%t A336003 u = u /. FindRoot[-Sqrt[2] + Sqrt[1 + E^(2 u)] + ArcTanh[Sqrt[2]] -
%t A336003 ArcTanh[Sqrt[1 + E^(2 u)]] - 1, {u, 0}, WorkingPrecision -> 100]
%t A336003 RealDigits[u][[1]]
%Y A336003 Cf. A336002.
%K A336003 nonn,cons
%O A336003 0,1
%A A336003 _Clark Kimberling_, Jul 06 2020