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 A387448 #9 Aug 31 2025 10:24:02 %S A387448 9,9,3,7,1,2,2,0,9,8,9,3,2,4,2,5,8,3,5,3,3,1,4,8,2,4,1,9,4,7,3,7,8,6, %T A387448 9,7,1,5,2,6,3,5,4,9,5,7,8,2,0,7,3,2,1,4,9,2,7,7,5,6,5,0,2,1,5,9,5,1, %U A387448 0,3,8,0,9,6,8,8,9,0,9,4,4,6,6,9,0,9,9,5,7,6,4,8,7,2,7,0,6,4,3,8,2,2,3,5,4,3,0,0,9,0,4,5,5,3,7,6,6,8 %N A387448 Decimal expansion of cos(Pi/28). %H A387448 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 A387448 <a href="/index/Al#algebraic_12">Index entries for algebraic numbers, degree 12</a> %F A387448 Equals sin(13*Pi/28) = sqrt( (A232735+1)/2 ) = 2F1(-1/14,1/14;1/2;1/2). %F A387448 Largest of the 12 real-valued roots of 4096*x^12 -12288*x^10 +13568*x^8 -6656*x^6 +1376*x^4 -96*x^2 +1 =0. %e A387448 0.99371220989324258353... %Y A387448 Cf. A132744. %K A387448 nonn,cons,new %O A387448 0,1 %A A387448 _R. J. Mathar_, Aug 29 2025