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 A019904 #25 Jul 08 2025 07:43:29 %S A019904 1,0,5,1,0,4,2,3,5,2,6,5,6,7,6,4,6,2,5,1,1,5,0,2,3,8,0,1,3,9,8,8,1,9, %T A019904 1,5,2,5,0,2,4,6,6,4,9,5,4,5,6,8,6,8,8,2,8,7,8,6,6,1,5,6,8,1,8,3,7,8, %U A019904 1,9,1,0,8,1,0,6,1,4,4,1,6,7,9,7,9,3,7,5,0,4,6,7,4,7,7,0,2,0,0 %N A019904 Decimal expansion of tangent of 6 degrees. %C A019904 Also the decimal expansion of cotangent of 84 degrees. - _Mohammad K. Azarian_, Jun 30 2013 %C A019904 An algebraic integer of degree 8. - _Charles R Greathouse IV_, Nov 17 2017 %H A019904 Ivan Panchenko, <a href="/A019904/b019904.txt">Table of n, a(n) for n = 0..1000</a> %H A019904 Wikipedia, <a href="http://en.wikipedia.org/wiki/Exact_trigonometric_constants">Exact trigonometric constants</a> %H A019904 <a href="/index/Al#algebraic_08">Index entries for algebraic numbers, degree 8</a> %t A019904 RealDigits[Tan[6 Degree],10,120][[1]] (* _Harvey P. Dale_, Jun 18 2024 *) %o A019904 (PARI) tan(Pi/30) \\ _Charles R Greathouse IV_, Nov 17 2017 %K A019904 nonn,cons %O A019904 0,3 %A A019904 _N. J. A. Sloane_