%I #12 Feb 24 2023 11:55:15
%S 1,2,2,5,1,7,5,3,2,3,1,5,9,5,3,7,8,8,7,8,0,2,9,4,7,7,7,4,0,2,8,8,2,0,
%T 9,8,0,8,8,3,0,8,1,0,6,7,4,8,1,4,2,3,6,7,2,8,8,7,4,8,0,0,4,5,0,9,1,1,
%U 7,8,4,5,2,1,5,3,9,3,2,8,7,7,4,2,3,0,6,6,7,3,0,7,1,8,1,5,7,5,3,1,5,7,2,6,6
%N Decimal expansion of 2*sqrt(3)/(9*Pi).
%C The ratio of the volume of a regular tetrahedron to the volume of the circumscribed sphere. (The MathWorld link shows that the circumradius for a tetrahedron with side length a is a*sqrt(6)/4.)
%H Frank Jackson and Eric W. Weisstein, <a href="http://mathworld.wolfram.com/Tetrahedron.html">Tetrahedron</a>
%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F 2*sqrt(3)/(9*Pi) = A010469/(9*A000796) = (2/9)*A002194/A000796 = (2/9)*A002194*A049541 = 2*A020784/A000796 = 2*3^(-3/2)/Pi.
%e 0.122517532315953788780294777402882098...
%t RealDigits[(2Sqrt[3])/(9Pi),10,120][[1]] (* _Harvey P. Dale_, Nov 17 2013 *)
%o (PARI) 2*3^(-3/2)/Pi
%Y Cf. A000796, A002194, A010469, A049541, A020784.
%K cons,nonn
%O 0,2
%A _Rick L. Shepherd_, Sep 30 2009