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 A019967 #16 Sep 08 2022 08:44:44 %S A019967 2,6,0,5,0,8,9,0,6,4,6,9,3,8,0,1,5,3,6,2,5,8,4,1,2,3,3,6,4,3,3,5,4,1, %T A019967 1,8,6,0,9,3,2,8,7,2,6,7,9,4,3,1,9,5,0,2,3,7,5,2,0,1,0,9,6,8,0,0,2,4, %U A019967 1,4,2,6,5,5,8,1,3,9,1,6,6,6,1,4,4,8,1,8,6,7,5,8,4,0,6,0,3,5,2 %N A019967 Decimal expansion of tangent of 69 degrees. %C A019967 Also the decimal expansion of cotangent of 21 degrees. - _Ivan Panchenko_, Sep 01 2014 %H A019967 Ivan Panchenko, <a href="/A019967/b019967.txt">Table of n, a(n) for n = 1..1000</a> %H A019967 Wikipedia, <a href="http://en.wikipedia.org/wiki/Exact_trigonometric_constants">Exact trigonometric constants</a> %e A019967 2.605089064693801536258412336433541186093287267943195023752... %t A019967 RealDigits[Tan[23*Pi/60], 10, 100][[1]] (* _G. C. Greubel_, Nov 20 2018 *) %o A019967 (PARI) default(realprecision, 100); tan(23*Pi/60) \\ _G. C. Greubel_, Nov 21 2018 %o A019967 (Magma) SetDefaultRealField(RealField(100)); R:= RealField(); Tan(23*Pi(R)/60); // _G. C. Greubel_, Nov 21 2018 %o A019967 (Sage) numerical_approx(tan(23*pi/60), digits=100) # _G. C. Greubel_, Nov 21 2018 %Y A019967 Cf. A019878 (sine of 69 degrees). %K A019967 nonn,cons %O A019967 1,1 %A A019967 _N. J. A. Sloane_