A102520 - OEIS

%I #19 Sep 28 2022 13:50:32

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

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

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

%N Decimal expansion of 1-(9*sqrt(3))/(8*Pi).

%C This is the probability that a Gaussian triangle in 5 dimensions is obtuse.

%C Also, the probability that the distance between 2 randomly selected points within a 4-dimensional ball will be smaller than its radius. - _Amiram Eldar_, Apr 14 2022

%H G. C. Greubel, <a href="/A102520/b102520.txt">Table of n, a(n) for n = 0..5000</a>

%H Steven R. Finch, <a href="/A102519/a102519.pdf">Random Triangles</a>, January 21, 2010. [Cached copy, with permission of the author]

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BallLinePicking.html">Ball Line Picking</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GaussianTrianglePicking.html">Gaussian Triangle Picking</a>.

%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>

%t RealDigits[1 - (9*Sqrt[3])/(8*Pi), 10, 50][[1]] (* _G. C. Greubel_, Jun 02 2017 *)

%o (PARI) 1 - (9*sqrt(3))/(8*Pi) \\ _G. C. Greubel_, Jun 01 2017

%Y Cf. A102519.

%K cons,nonn

%O 0,1

%A Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 13 2005