Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #26 Mar 11 2023 07:56:24
%S 1,3,1,6,5,2,4,9,7,5,8,7,3,9,5,8,5,3,4,7,1,5,2,6,4,5,7,4,0,9,7,1,7,1,
%T 0,3,5,9,2,8,1,4,1,0,2,2,2,3,2,3,7,5,7,3,5,5,3,5,6,5,3,2,5,7,8,9,7,5,
%U 9,8,3,9,0,1,0,6,2,2,0,2,8,3,0,9,1,0,0,7,8,0,6,7,5,0,3,3,2,3,1,8,7,7,9,8,2,3,0,6,0,4,2
%N Decimal expansion of tan(Pi/24).
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Trigonometric_constants_expressed_in_real_radicals">Trigonometric constants expressed in real radicals</a>
%F Equals sqrt( (2-sqrt(2+sqrt(3)))/(2+sqrt(2+sqrt(3))) ).
%F Equals (sqrt(2)-1)*(sqrt(3)-sqrt(2)) = sqrt(2)-sqrt(3)+sqrt(6)-2.
%e 0.13165249758739585347152...
%t RealDigits[Tan[Pi/24], 10, 100][[1]] (* _Amiram Eldar_, Apr 27 2021 *)
%o (PARI) tan(Pi/24)
%o (PARI) sqrt((2-sqrt(2+sqrt(3)))/(2+sqrt(2+sqrt(3))))
%o (PARI) (sqrt(2)-1)*(sqrt(3)-sqrt(2))
%Y Cf. A144982 (cos (Pi/24)).
%K nonn,cons,easy
%O 0,2
%A _Seiichi Manyama_, Apr 04 2021