A378353 Decimal expansion of the inradius of a (small) triakis octahedron with unit shorter edge length.

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

Offset

0,1

Comments

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

Links

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

Formula

Equals sqrt(23/68 + 4*sqrt(2)/17) = sqrt(23/68 + A010487/17).

Example

0.81914066340325716171549134573565316624155520306132...

Mathematica

First[RealDigits[Sqrt[23/68 + Sqrt[32]/17], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["TriakisOctahedron", "Inradius"], 10, 100]]

Crossrefs

Cf. A378351 (surface area), A378352 (volume), A201488 (midradius), A378354 (dihedral angle).

Cf. A010487.

Sequence in context: A141228 A133820 A258718 * A019864 A230151 A308043

Adjacent sequences: A378343 A378351 A378352 * A378354 A378355 A378357

Keyword

nonn,cons,easy,new

Author

Paolo Xausa, Nov 23 2024

Status

approved