A378204 Decimal expansion of the surface area of a triakis tetrahedron with unit shorter edge length.

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

Offset: 1

Author

Paolo Xausa, Nov 20 2024

Keywords

• nonn
• cons
• easy

Comments

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

Examples

			5.5277079839256664151915545611178111398784809093...
		

Links

• Eric Weisstein's World of Mathematics, Triakis Tetrahedron.
• Wikipedia, Triakis tetrahedron.
• Index entries for algebraic numbers, degree 2.

Crossrefs

Cf. A378205 (volume), A378206 (inradius), A378207 (midradius), A378208 (dihedral angle).

Cf. A377274 (surface area of a truncated tetrahedron with unit edge).

Cf. A010468.

Programs

Mathematica

First[RealDigits[5*Sqrt[11]/3, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["TriakisTetrahedron", "SurfaceArea"], 10, 100]]

Formula

Equals (5/3)*sqrt(11) = (5/3)*A010468.