A378205 Decimal expansion of the volume of a triakis tetrahedron with unit shorter edge length.

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

Offset

0,1

Comments

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

Links

Table of n, a(n) for n=0..89.

Eric Weisstein's World of Mathematics, Triakis Tetrahedron.

Wikipedia, Triakis tetrahedron.

Formula

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

Example

0.9820927516479826727789505029234014434511610245673...

Mathematica

First[RealDigits[25/36*Sqrt[2], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["TriakisTetrahedron", "Volume"], 10, 100]]

Crossrefs

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

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

Cf. A002193.

Sequence in context: A249677 A094135 A021897 * A225458 A092172 A133619

Adjacent sequences: A378202 A378203 A378204 * A378206 A378207 A378208

Keyword

nonn,cons,easy

Author

Paolo Xausa, Nov 20 2024

Status

approved