This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A195698 #17 Nov 21 2024 07:53:19 %S A195698 2,1,8,6,2,7,6,0,3,5,4,6,5,2,8,3,9,6,0,2,9,8,7,8,6,2,8,0,7,6,3,7,4,5, %T A195698 1,2,9,9,5,3,7,5,4,7,0,4,3,6,5,1,0,0,3,3,0,0,1,5,2,4,6,4,6,2,9,8,5,9, %U A195698 0,4,3,6,0,3,8,2,2,3,2,5,4,3,2,4,0,6,4,3,2,2,2,7,5,6,4,8,8,9,9,4 %N A195698 Decimal expansion of arccos(-sqrt(1/3)). %C A195698 Dihedral angle between mixed type faces of the truncated octahedron. - _R. J. Mathar_, Mar 24 2012 %H A195698 G. C. Greubel, <a href="/A195698/b195698.txt">Table of n, a(n) for n = 1..5000</a> %H A195698 Wikipedia, <a href="http://en.wikipedia.org/wiki/Truncated_octahedron">Truncated Octahedron</a>. %H A195698 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %F A195698 Equals Pi - arcsin(sqrt(2/3)) = Pi - arctan(sqrt(2)). - _Amiram Eldar_, Jul 08 2023 %e A195698 arccos(-1/sqrt(3)) = 2.1862760354... %t A195698 (See A195695.) %t A195698 RealDigits[ArcCos[-1/Sqrt[3]], 10, 50][[1]] (* _G. C. Greubel_, Nov 18 2017 *) %o A195698 (PARI) acos(-1/sqrt(3)) \\ _G. C. Greubel_, Nov 18 2017 %o A195698 (Magma) [Arccos(-1/Sqrt(3))]; // _G. C. Greubel_, Nov 18 2017 %Y A195698 Cf. A195695. %K A195698 nonn,cons %O A195698 1,1 %A A195698 _Clark Kimberling_, Sep 23 2011