OFFSET
0,1
COMMENTS
The corresponding real part is in A232735.
Root of the equation 1 - 4*x - 4*x^2 + 8*x^3 = 0. - Vaclav Kotesovec, Apr 04 2021
LINKS
Stanislav Sykora, Table of n, a(n) for n = 0..1000
FORMULA
Equals cos(3*Pi/7). - G. C. Greubel, Sep 04 2022
EXAMPLE
0.222520933956314404288902564496794759466355568764544955311987...
MATHEMATICA
RealDigits[Cos[3*Pi/7], 10, 120][[1]] (* G. C. Greubel, Sep 04 2022 *)
PROG
(Magma) R:= RealField(120); Cos(3*Pi(R)/7); // G. C. Greubel, Sep 04 2022
(SageMath) numerical_approx(cos(3*pi/7), digits=120) # G. C. Greubel, Sep 04 2022
CROSSREFS
KEYWORD
AUTHOR
Stanislav Sykora, Nov 29 2013
STATUS
approved