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 A201890 #8 Feb 07 2025 16:44:07
%S A201890 2,5,1,2,8,6,2,4,1,7,2,5,2,3,3,9,3,5,3,9,6,5,4,7,5,2,3,3,2,1,8,4,3,2,
%T A201890 6,5,3,8,3,2,8,3,3,6,6,3,4,0,2,6,4,7,4,2,2,2,5,1,7,8,9,4,5,4,0,9,6,6,
%U A201890 0,0,9,5,7,0,8,2,1,0,3,8,0,7,0,6,7,3,2,9,5,0,1,8,9,4,5,0,1,6,9
%N A201890 Decimal expansion of the nonzero number x satisfying x^2+2x+1=e^x.
%C A201890 See A201741 for a guide to related sequences. The Mathematica program includes a graph.
%H A201890 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A201890 x=2.51286241725233935396547523321843265383...
%t A201890 a = 1; b = 2; c = 1;
%t A201890 f[x_] := a*x^2 + b*x + c; g[x_] := E^x
%t A201890 Plot[{f[x], g[x]}, {x, -1, 3}, {AxesOrigin -> {0, 0}}]
%t A201890 r = x /. FindRoot[f[x] == g[x], {x, 2.5, 2.6}, WorkingPrecision -> 110]
%t A201890 RealDigits[r] (* A201890 *)
%Y A201890 Cf. A201741.
%K A201890 nonn,cons
%O A201890 1,1
%A A201890 _Clark Kimberling_, Dec 06 2011