A378352 Decimal expansion of the volume of a (small) triakis octahedron with unit shorter edge length.

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

Offset: 1

Author

Paolo Xausa, Nov 23 2024

Keywords

• nonn
• cons
• easy

Comments

The (small) triakis octahedron is the dual polyhedron of the truncated cube.

Examples

			2.9142135623730950488016887242096980785696718753769...
		

Links

• Eric Weisstein's World of Mathematics, Small Triakis Octahedron.
• Wikipedia, Triakis octahedron.

Crossrefs

Cf. A378351 (surface area), A378353 (inradius), A201488 (midradius), A378354 (dihedral angle).

Cf. A377299 (volume of a truncated cube with unit edge).

Cf. A156035.

Essentially the same as A002193 and A188582.

Programs

Mathematica

First[RealDigits[Sqrt[2] + 3/2, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["TriakisOctahedron", "Volume"], 10, 100]]

Formula

Equals sqrt(2) + 3/2 = A002193 + 3/2.

Equals A156035/2. - Hugo Pfoertner, Nov 24 2024