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 A387446 #7 Aug 31 2025 06:36:32 %S A387446 9,9,2,7,0,8,8,7,4,0,9,8,0,5,3,9,9,2,8,0,0,7,5,1,6,4,9,4,9,2,5,2,0,1, %T A387446 7,9,3,4,3,6,7,5,6,3,2,9,7,0,1,6,6,8,5,5,7,7,0,9,9,7,5,6,0,5,1,1,8,6, %U A387446 7,4,4,6,2,1,3,9,6,2,9,1,4,5,5,8,6,1,6,9,4,9,3,4,2,7,8,2,4,0,4,4,1,8,9,9,1,1,8,6,0,7,1,4,1,7,7,0,9,1 %N A387446 Decimal expansion of cos(Pi/26). %H A387446 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 A387446 <a href="/index/Al#algebraic_12">Index entries for algebraic numbers, degree 12</a> %F A387446 Equals sin(6*Pi/13) = sqrt( (A387441+1)/2 ). %F A387446 Largest of the 12 real-valued roots of 4096*x^12 -13312*x^10 +16640*x^8 -9984*x^6 +2912*x^4 -364*x^2 +13 = 0. %e A387446 0.99270887409805399280... %K A387446 nonn,cons,new %O A387446 0,1 %A A387446 _R. J. Mathar_, Aug 29 2025