A378205 - OEIS

%I #9 Nov 22 2024 11:07:06

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

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

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

%N Decimal expansion of the volume of a triakis tetrahedron with unit shorter edge length.

%C The triakis tetrahedron is the dual polyhedron of the truncated tetrahedron.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TriakisTetrahedron.html">Triakis Tetrahedron</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Triakis_tetrahedron">Triakis tetrahedron</a>.

%F Equals (25/36)*sqrt(2) = (25/36)*A002193.

%e 0.9820927516479826727789505029234014434511610245673...

%t First[RealDigits[25/36*Sqrt[2], 10, 100]] (* or *)

%t First[RealDigits[PolyhedronData["TriakisTetrahedron", "Volume"], 10, 100]]

%Y Cf. A378204 (surface area), A378206 (inradius), A378207 (midradius), A378208 (dihedral angle).

%Y Cf. A377275 (volume of a truncated tetrahedron with unit edge).

%Y Cf. A002193.

%K nonn,cons,easy

%O 0,1

%A _Paolo Xausa_, Nov 20 2024