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A019964 Decimal expansion of tangent of 66 degrees.

%I A019964 #19 Sep 06 2025 09:16:16
%S A019964 2,2,4,6,0,3,6,7,7,3,9,0,4,2,1,6,0,5,4,1,6,3,3,2,1,4,3,8,4,1,6,4,0,9,
%T A019964 1,5,9,1,4,0,3,6,3,1,0,1,0,2,6,8,9,7,0,8,1,4,1,0,4,2,8,3,5,4,8,4,5,3,
%U A019964 3,1,9,8,5,8,3,8,7,9,3,4,1,3,2,3,6,0,7,8,6,9,4,7,7,6,1,9,5,1,4
%N A019964 Decimal expansion of tangent of 66 degrees.
%C A019964 Also the decimal expansion of cotangent of 24 degrees. - _Ivan Panchenko_, Sep 01 2014
%C A019964 A root of 1-92*x^2+134*x^4-28*x^6+x^8=0. - _R. J. Mathar_, Sep 06 2025
%H A019964 Ivan Panchenko, <a href="/A019964/b019964.txt">Table of n, a(n) for n = 1..1000</a>
%H A019964 Wikipedia, <a href="http://en.wikipedia.org/wiki/Exact_trigonometric_constants">Exact trigonometric constants</a>
%H A019964 <a href="/index/Al#algebraic_08">Index entries for algebraic numbers, degree 8</a>
%F A019964 Equals A019857/(1-A019851) = A019875/A019833. - _R. J. Mathar_, Sep 06 2025
%e A019964 tan(11*Pi/30) = 2.24603677390421605416332143841640915914036310102689708141...
%t A019964 RealDigits[Tan[73*Pi/180], 10, 100][[1]] (* _G. C. Greubel_, Nov 21 2018 *)
%o A019964 (PARI) default(realprecision, 100); tan(11*Pi/30) \\ _G. C. Greubel_, Nov 21 2018
%o A019964 (Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(11*Pi(R)/30); // _G. C. Greubel_, Nov 21 2018
%o A019964 (Sage) numerical_approx(tan(11*pi/30), digits=100) # _G. C. Greubel_, Nov 21 2018
%Y A019964 Cf. A019875 (sine 66 degrees).
%K A019964 nonn,cons,changed
%O A019964 1,1
%A A019964 _N. J. A. Sloane_