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 A387451 #9 Aug 31 2025 06:38:56 %S A387451 9,9,5,7,3,4,1,7,6,2,9,5,0,3,4,5,2,1,8,7,1,1,9,1,1,7,8,9,0,5,4,8,1,7, %T A387451 8,3,9,0,2,7,2,4,6,1,7,6,1,6,2,9,9,1,9,8,3,7,1,9,0,3,0,1,6,3,0,8,7,0, %U A387451 7,1,5,9,4,1,7,8,5,3,4,0,8,0,3,7,5,4,8,4,2,4,7,3,7,0,1,2,9,8,4,1,7,0,4,5,7,8,6,4,3,1,0,9,0,1,0,7,5,6 %N A387451 Decimal expansion of cos(Pi/34). %H A387451 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 A387451 <a href="/index/Al#algebraic_16">Index entries for algebraic numbers, degree 16</a> %F A387451 Equals sin(8*Pi/17)= sqrt( (A210649+1)/2 ). %F A387451 Largest of the 16 real-valued roots of 65536*x^16 -278528*x^14 +487424*x^12 -452608*x^10 +239360*x^8 -71808*x^6 +11424*x^4 -816*x^2 +17 =0. %e A387451 0.99573417629503452187... %Y A387451 Cf. A210649. %K A387451 nonn,cons,new %O A387451 0,1 %A A387451 _R. J. Mathar_, Aug 29 2025