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 A198987 #8 Feb 07 2025 19:47:08
%S A198987 6,6,8,0,2,7,8,4,7,4,5,3,0,5,4,0,7,4,5,0,2,2,2,0,0,5,6,3,7,3,9,8,6,8,
%T A198987 5,1,2,1,5,7,9,0,2,6,8,8,8,4,0,9,1,8,5,4,6,5,4,3,7,6,9,1,1,6,4,6,9,0,
%U A198987 9,7,0,4,3,4,0,1,0,5,4,1,5,5,4,1,4,6,8,1,7,2,3,5,5,4,3,3,0,9,4
%N A198987 Decimal expansion of x>0 satisfying 4*x^2-cos(x)=1.
%C A198987 See A198755 for a guide to related sequences. The Mathematica program includes a graph.
%H A198987 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198987 0.668027847453054074502220056373986851215790...
%t A198987 a = 4; b = -1; c = 1;
%t A198987 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c
%t A198987 Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]
%t A198987 r = x /. FindRoot[f[x] == g[x], {x, .66, .67}, WorkingPrecision -> 110]
%t A198987 RealDigits[r] (* A198987 *)
%Y A198987 Cf. A198755.
%K A198987 nonn,cons
%O A198987 0,1
%A A198987 _Clark Kimberling_, Nov 01 2011