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 A198842 #8 Feb 07 2025 16:44:05
%S A198842 1,0,2,9,7,0,4,0,0,0,7,3,6,0,5,4,5,5,8,4,1,1,6,7,9,2,6,7,9,8,2,9,0,6,
%T A198842 9,5,8,9,4,5,5,8,8,8,3,4,8,1,5,9,5,7,8,4,0,6,8,8,0,7,9,2,9,7,4,9,5,7,
%U A198842 2,7,6,2,9,7,4,3,4,7,2,6,5,2,4,8,3,5,7,7,1,8,8,8,9,1,0,5,9,6,9
%N A198842 Decimal expansion of x>0 satisfying x^2-4*cos(x)=-1.
%C A198842 See A198755 for a guide to related sequences. The Mathematica program includes a graph.
%H A198842 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198842 1.0297040007360545584116792679829069589455888...
%t A198842 a = 1; b = -4; c = -1;
%t A198842 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c
%t A198842 Plot[{f[x], g[x]}, {x, -3, 3}, {AxesOrigin -> {0, 0}}]
%t A198842 r = x /. FindRoot[f[x] == g[x], {x, 1.02, 1.03}, WorkingPrecision -> 110]
%t A198842 RealDigits[r] (* A198842 *)
%Y A198842 Cf. A198755.
%K A198842 nonn,cons
%O A198842 1,3
%A A198842 _Clark Kimberling_, Oct 30 2011