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 A197490 #11 Feb 16 2025 05:24:14
%S A197490 5,6,4,4,2,5,4,7,6,0,6,2,6,5,9,0,9,9,3,8,4,0,0,3,2,2,8,9,3,7,7,8,8,2,
%T A197490 9,7,6,7,7,4,9,8,5,5,2,8,2,2,8,6,1,8,0,6,1,3,5,9,1,0,5,4,9,2,1,7,4,1,
%U A197490 1,0,3,1,7,3,3,4,6,2,5,7,9,7,5,7,0,3,5,6,1,7,0,5,0,5,5,0,4,2,9
%N A197490 Decimal expansion of least x > 0 having cos(x) = cos(2*Pi*x)^2.
%C A197490 The Mathematica program includes a graph. See A197476 for a guide for the least x > 0 satisfying cos(b*x) = cos(c*x)^2 for selected b and c.
%C A197490 This number is irrational. I cannot prove it to be algebraic or transcendental. - _Charles R Greathouse IV_, Feb 16 2025
%e A197490 0.564425476062659099384003228937788297677...
%t A197490 b = 1; c = 2 Pi; f[x_] := Cos[x]
%t A197490 t = x /. FindRoot[f[b*x] == f[c*x]^2, {x, .56, .57}, WorkingPrecision -> 110]
%t A197490 RealDigits[t] (* A197490 *)
%t A197490 Plot[{f[b*x], f[c*x]^2}, {x, 0, Pi/4}]
%Y A197490 Cf. A197476.
%K A197490 nonn,cons
%O A197490 0,1
%A A197490 _Clark Kimberling_, Oct 15 2011