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 A019949 #14 Sep 08 2022 08:44:44 %S A019949 1,2,3,4,8,9,7,1,5,6,5,3,5,0,5,1,3,9,8,5,5,6,1,7,4,6,9,5,3,7,5,9,3,5, %T A019949 1,4,0,0,5,3,6,2,5,5,8,4,0,7,7,9,7,6,5,3,6,4,2,1,2,5,9,2,0,8,8,4,3,7, %U A019949 5,7,3,0,1,3,4,7,7,4,0,2,1,4,1,2,3,1,2,8,7,0,4,0,6,4,3,5,3,8,1 %N A019949 Decimal expansion of tangent of 51 degrees. %C A019949 Also the decimal expansion of cotangent of 39 degrees. - _Ivan Panchenko_, Sep 01 2014 %H A019949 Ivan Panchenko, <a href="/A019949/b019949.txt">Table of n, a(n) for n = 1..1000</a> %H A019949 Wikipedia, <a href="http://en.wikipedia.org/wiki/Exact_trigonometric_constants">Exact trigonometric constants</a> %F A019949 Equals cot(13*Pi/60) = ((2+sqrt(3))*(3-sqrt(5)) -2)*(2 + sqrt(2*(5 + sqrt(5))))/4. - _G. C. Greubel_, Nov 23 2018 %e A019949 1.2348971565350513985561746953759351400536255840779765364212592... %t A019949 RealDigits[Tan[17*Pi/60], 10, 100][[1]] (* _G. C. Greubel_, Nov 23 2018 *) %t A019949 RealDigits[Tan[51 Degree],10,120][[1]] (* _Harvey P. Dale_, Jan 18 2021 *) %o A019949 (PARI) default(realprecision, 100); tan(17*Pi/60) \\ _G. C. Greubel_, Nov 23 2018 %o A019949 (Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(17*Pi(R)/60); // _G. C. Greubel_, Nov 23 2018 %o A019949 (Sage) numerical_approx(tan(17*pi/60), digits=100) # _G. C. Greubel_, Nov 23 2018 %Y A019949 Cf. A019860 (sine of 51 degrees). %K A019949 nonn,cons %O A019949 1,2 %A A019949 _N. J. A. Sloane_