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 A198990 #8 Feb 07 2025 19:45:39
%S A198990 1,0,5,9,4,0,8,7,6,9,0,7,0,0,3,7,4,7,8,4,5,4,1,9,3,2,2,5,6,9,2,3,6,5,
%T A198990 3,2,5,0,6,7,9,6,1,1,7,9,2,4,6,0,8,4,1,1,2,7,4,3,5,1,3,4,5,1,3,2,9,8,
%U A198990 1,2,6,1,3,0,5,6,8,6,3,5,6,1,1,1,4,2,4,4,9,1,4,0,0,3,3,7,3,5,1
%N A198990 Decimal expansion of x>0 satisfying 4*x^2-cos(x)=4.
%C A198990 See A198755 for a guide to related sequences. The Mathematica program includes a graph.
%H A198990 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198990 1.0594087690700374784541932256923653250679611...
%t A198990 a = 4; b = -1; c = 4;
%t A198990 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c
%t A198990 Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]
%t A198990 r = x /. FindRoot[f[x] == g[x], {x, 1.05, 1.06}, WorkingPrecision -> 110]
%t A198990 RealDigits[r] (* A198990 *)
%Y A198990 Cf. A198755.
%K A198990 nonn,cons
%O A198990 1,3
%A A198990 _Clark Kimberling_, Nov 01 2011