login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A232737 Decimal expansion of the real part of I^(1/8), or cos(Pi/16). 5

%I #28 Jun 29 2023 09:02:23

%S 9,8,0,7,8,5,2,8,0,4,0,3,2,3,0,4,4,9,1,2,6,1,8,2,2,3,6,1,3,4,2,3,9,0,

%T 3,6,9,7,3,9,3,3,7,3,0,8,9,3,3,3,6,0,9,5,0,0,2,9,1,6,0,8,8,5,4,5,3,0,

%U 6,5,1,3,5,4,9,6,0,5,0,6,3,9,1,5,0,6,4,9,8,5,8,5,3,3,0,0,7,6,3,2,5,9,8,9,4

%N Decimal expansion of the real part of I^(1/8), or cos(Pi/16).

%C The corresponding imaginary part is in A232738.

%H Stanislav Sykora, <a href="/A232737/b232737.txt">Table of n, a(n) for n = 0..1000</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Trigonometric_constants_expressed_in_real_radicals">Trigonometric constants expressed in real radicals</a>.

%F Equals (1/2) * sqrt(2+sqrt(2+sqrt(2))). - _Seiichi Manyama_, Apr 04 2021

%e 0.9807852804032304491261822361342390369739337308933360950029160885453...

%t RealDigits[Cos[Pi/16], 10, 120][[1]] (* _Amiram Eldar_, Jun 29 2023 *)

%o (PARI) real(I^(1/8)) \\ _Seiichi Manyama_, Apr 04 2021

%o (PARI) cos(Pi/16) \\ _Seiichi Manyama_, Apr 04 2021

%o (PARI) sqrt(2+sqrt(2+sqrt(2)))/2 \\ _Seiichi Manyama_, Apr 04 2021

%Y Cf. A232738 (imaginary part), A010503 (real(I^(1/2))), A010527 (real(I^(1/3))), A144981 (real(I^(1/4))), A019881 (real(I^(1/5))), A019884 (real(I^(1/6))), A232735 (real(I^(1/7))), A019889 (real(I^(1/9))), A019890 (real(I^(1/10))).

%K nonn,cons,easy

%O 0,1

%A _Stanislav Sykora_, Nov 29 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)