A378351 Decimal expansion of the surface area of a (small) triakis octahedron with unit shorter edge length.

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

Offset: 2

Author

Paolo Xausa, Nov 23 2024

Keywords

• nonn
• cons
• easy

Comments

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

Examples

			10.672941873983546705150008922490160564590104237715...
		

Links

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

Crossrefs

Cf. A378352 (volume), A378353 (inradius), A201488 (midradius), A378354 (dihedral angle).

Cf. A377298 (surface area of a truncated cube with unit edge).

Cf. A010487.

Programs

Mathematica

First[RealDigits[3*Sqrt[7 + Sqrt[32]], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["TriakisOctahedron", "SurfaceArea"], 10, 100]]

Formula

Equals 3*sqrt(7 + 4*sqrt(2)) = 3*sqrt(7 + A010487).