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 A019836 #27 Aug 29 2025 11:09:48 %S A019836 4,5,3,9,9,0,4,9,9,7,3,9,5,4,6,7,9,1,5,6,0,4,0,8,3,6,6,3,5,7,8,7,1,1, %T A019836 9,8,9,8,3,0,4,7,7,0,3,0,4,9,0,2,1,5,5,6,9,8,5,3,1,6,0,0,5,8,2,2,0,2, %U A019836 6,7,8,4,1,3,1,8,5,2,4,2,8,7,5,4,4,7,3,4,3,9,2,2,1,9,4,6,7,9,7 %N A019836 Decimal expansion of sine of 27 degrees. %C A019836 An algebraic number of degree 8 and denominator 2. - _Charles R Greathouse IV_, Aug 27 2017 %H A019836 Ivan Panchenko, <a href="/A019836/b019836.txt">Table of n, a(n) for n = 0..1000</a> %H A019836 Wikipedia, <a href="https://en.wikipedia.org/wiki/Trigonometric_constants_expressed_in_real_radicals">Trigonometric constants expressed in real radicals</a> %H A019836 <a href="/index/Al#algebraic_08">Index entries for algebraic numbers, degree 8</a> %F A019836 Equals A019827 * A019890 + A019818 * A019881 = A019833 * A019896 + A019812 * A019875. - _R. J. Mathar_, Jan 27 2021 %F A019836 Equals cos(7*Pi/20). 2*this^2-1 = -A019845. - _R. J. Mathar_, Aug 29 2025 %t A019836 RealDigits[Sin[27 Degree],10,120][[1]] (* _Harvey P. Dale_, Nov 09 2014 *) %o A019836 (PARI) cos(7*Pi/20) \\ _Charles R Greathouse IV_, Aug 27 2017 %K A019836 nonn,cons,changed %O A019836 0,1 %A A019836 _N. J. A. Sloane_