A387451 Decimal expansion of cos(Pi/34).

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, 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, 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

Offset

0,1

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

R. J. Mathar, Reduction formulas of the cosine of integer fractions of pi, (2008) vixra:2210.0026.

Index entries for algebraic numbers, degree 16

Formula

Equals sin(8*Pi/17)= sqrt( (A210649+1)/2 ).

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.

Example

0.995734176295034521871191178905481783902724617616...

Mathematica

First[RealDigits[Cos[Pi/34], 10, 100]] (* Paolo Xausa, Nov 18 2025 *)

Crossrefs

Cf. A210649.

Sequence in context: A131744 A076416 A201289 * A091133 A334452 A195480

Adjacent sequences: A387448 A387449 A387450 * A387452 A387453 A387454

Keyword

nonn,cons,easy

Author

R. J. Mathar, Aug 29 2025

Status

approved