0,1

This sequence is also decimal expansion of cosine of 51 degrees. - Mohammad K. Azarian, Jun 29 2013

An algebraic number of degree 16 and denominator 2. - Charles R Greathouse IV, Nov 05 2017

Ivan Panchenko, Table of n, a(n) for n = 0..1000

Wikipedia, Exact trigonometric constants

RealDigits[Sin[39 Degree], 10, 120][[1]] (* Harvey P. Dale, Oct 02 2015 *)

(PARI) sin(13/60*Pi) \\ Charles R Greathouse IV, Nov 05 2017

Sequence in context: A201324 A107826 A078756 * A246967 A215261 A132826

Adjacent sequences: A019845 A019846 A019847 * A019849 A019850 A019851

nonn,cons

N. J. A. Sloane.

approved