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 A387444 #9 Aug 31 2025 06:35:42 %S A387444 9,9,0,6,8,5,9,4,6,0,3,6,3,3,0,7,5,2,3,4,2,3,2,2,9,6,0,0,9,6,2,0,6,0, %T A387444 0,5,1,3,9,9,9,9,1,8,3,4,5,4,8,2,4,3,9,0,6,6,0,6,5,1,3,0,4,1,9,9,7,9, %U A387444 6,6,4,4,9,1,2,0,1,4,8,0,5,7,9,6,9,2,2,6,0,4,2,7,1,9,2,6,9,6,9,2,9,7,4,0,1,4,5,3,7,9,9,1,4,5,5,2,5,4 %N A387444 Decimal expansion of cos(Pi/23). %H A387444 R. J. Mathar, <a href="https://vixra.org/abs/2210.0026">Reduction formulas of the cosine of integer fractions of pi</a>, (2008) vixra:2210.0026 %H A387444 <a href="/index/Al#algebraic_11">Index entries for algebraic numbers, degree 11</a> %F A387444 Equals sin(21*Pi/46). %F A387444 Largest of the 11 real-valued roots of 2048*x^11 -1024*x^10 -5120*x^9 +2304*x^8 +4608*x^7 -1792*x^6 -1792*x^5 +560*x^4 +280*x^3 -60*x^2 -12*x +1 = 0. %e A387444 0.99068594603633075234... %Y A387444 Cf. A019690. %K A387444 nonn,cons,new %O A387444 0,1 %A A387444 _R. J. Mathar_, Aug 29 2025