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 A198821 #10 Feb 07 2025 16:44:05
%S A198821 1,2,6,5,4,2,3,7,0,5,8,6,9,3,3,4,9,5,5,9,4,9,5,6,9,3,2,5,7,5,5,3,2,7,
%T A198821 0,5,6,0,7,1,8,3,2,1,7,6,1,7,7,6,7,9,8,0,5,4,1,8,2,7,8,3,4,7,4,4,9,1,
%U A198821 6,3,5,0,6,5,0,1,4,0,7,1,5,6,7,5,2,9,2,4,8,0,0,7,6,2,2,8,8,7,9
%N A198821 Decimal expansion of x>0 satisfying x^2-2*cos(x)=1.
%C A198821 See A198755 for a guide to related sequences. The Mathematica program includes a graph.
%H A198821 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.
%e A198821 1.265423705869334955949569325755327056071832...
%t A198821 a = 1; b = -2; c = 1;
%t A198821 f[x_] := a*x^2 + b*Cos[x]; g[x_] := c
%t A198821 Plot[{f[x], g[x]}, {x, -3, 3}, {AxesOrigin -> {0, 0}}]
%t A198821 r = x /. FindRoot[f[x] == g[x], {x, 1.2, 1.3}, WorkingPrecision -> 110]
%t A198821 RealDigits[r] (* A198821 *)
%Y A198821 Cf. A198755.
%K A198821 nonn,cons
%O A198821 1,2
%A A198821 _Clark Kimberling_, Oct 30 2011