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 A019813 #21 Aug 21 2023 11:49:08
%S A019813 0,6,9,7,5,6,4,7,3,7,4,4,1,2,5,3,0,0,7,7,5,9,5,8,8,3,5,1,9,4,1,4,3,3,
%T A019813 2,8,6,0,0,9,0,3,2,0,1,6,5,2,7,9,6,5,2,5,0,4,3,6,1,7,2,9,6,1,3,7,0,7,
%U A019813 1,1,2,7,0,6,6,7,8,9,1,2,2,9,1,2,5,3,7,8,5,6,8,2,8,0,7,4,2,9,2,3
%N A019813 Decimal expansion of sine of 4 degrees.
%C A019813 An algebraic number of degree 24 and denominator 2. - _Charles R Greathouse IV_, Aug 27 2017
%H A019813 Ivan Panchenko, <a href="/A019813/b019813.txt">Table of n, a(n) for n = 0..1000</a>
%H A019813 <a href="/index/Al#algebraic_24">Index entries for algebraic numbers, degree 24</a>
%F A019813 Equals 2*A019811*A019897. - _R. J. Mathar_, Jan 17 2021
%e A019813 0.06975...
%t A019813 Join[{0},RealDigits[Sin[4 Degree],10,120][[1]]] (* _Harvey P. Dale_, Oct 07 2019 *)
%o A019813 (PARI) sin(Pi/45) \\ _Charles R Greathouse IV_, Aug 27 2017
%K A019813 nonn,cons
%O A019813 0,2
%A A019813 _N. J. A. Sloane_
%E A019813 Zero added in front by _R. J. Mathar_, Feb 05 2009