%I #28 Aug 21 2023 11:27:40
%S 1,0,4,5,2,8,4,6,3,2,6,7,6,5,3,4,7,1,3,9,9,8,3,4,1,5,4,8,0,2,4,9,8,1,
%T 1,9,0,8,0,6,5,5,8,6,9,4,7,4,5,9,3,1,1,3,9,9,3,2,7,5,4,7,6,7,1,2,4,8,
%U 4,6,5,0,6,9,3,1,8,0,0,4,6,8,2,8,1,8,0,3,9,8,7,9,8,6,0,4,4,2,6
%N Decimal expansion of sine of 6 degrees.
%C Decimal expansion of 1/8 (-1 - sqrt(5) + sqrt(6*(5 - sqrt(5)))). - _Artur Jasinski_, Oct 28 2008
%H Ivan Panchenko, <a href="/A019815/b019815.txt">Table of n, a(n) for n = 0..1000</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Exact_trigonometric_constants">Exact trigonometric constants</a>
%H <a href="/index/Al#algebraic_04">Index entries for algebraic numbers, degree 4</a>
%F Equals cos(7*Pi/15) = -cos(8*Pi/15) = 2F1(6/5,-1/5;1/2;3/4) / 2 = -2F1(13/10,-3/10;1/2;3/4) / 2. - _R. J. Mathar_, Oct 27 2008
%F Equals 2*A019812*A019896. - _R. J. Mathar_, Jan 17 2021
%e 0.10452846...
%t First[RealDigits[1/8 (-1 - Sqrt[5] + Sqrt[6 (5 - Sqrt[5])]), 10, 100]] (* _Artur Jasinski_, Oct 28 2008 *)
%t RealDigits[Sin[6 Degree],10,120][[1]] (* _Harvey P. Dale_, Apr 27 2012 *)
%o (PARI) sin(Pi/30) \\ _Charles R Greathouse IV_, Jan 30 2016
%K nonn,cons
%O 0,3
%A _N. J. A. Sloane_