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 A198988 #8 Feb 07 2025 19:45:35
%S A198988 8,1,8,9,8,7,3,6,8,4,4,8,7,3,3,4,3,7,7,4,7,8,2,4,3,5,5,1,6,7,7,0,6,6,
%T A198988 4,4,3,6,9,2,5,9,8,9,2,5,4,8,1,8,5,0,3,4,8,8,4,1,2,2,9,0,2,9,3,4,8,7,
%U A198988 3,7,2,2,9,3,4,8,1,0,7,1,8,1,4,5,1,7,8,4,0,5,2,0,4,7,3,0,6,9,7
%N A198988 Decimal expansion of x>0 satisfying 4*x^2-cos(x)=2.
%C A198988 See A198755 for a guide to related sequences. The Mathematica program includes a graph.
%H A198988 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198988 0.818987368448733437747824355167706644369...
%t A198988 a = 4; b = -1; c = 2;
%t A198988 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c
%t A198988 Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]
%t A198988 r = x /. FindRoot[f[x] == g[x], {x, .81, .82}, WorkingPrecision -> 110]
%t A198988 RealDigits[r] (* A198988 *)
%Y A198988 Cf. A198755.
%K A198988 nonn,cons
%O A198988 0,1
%A A198988 _Clark Kimberling_, Nov 01 2011