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

1,1

Comments

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

Links

Table of n, a(n) for n=1..90.

Eric Weisstein's World of Mathematics, Triakis Tetrahedron.

Wikipedia, Triakis tetrahedron.

Index entries for algebraic numbers, degree 2.

Formula

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

Example

5.5277079839256664151915545611178111398784809093...

Mathematica

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

Crossrefs

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

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

Cf. A010468.

Sequence in context: A381117 A019602 A153839 * A322159 A023580 A021648

Adjacent sequences: A378201 A378202 A378203 * A378205 A378206 A378207

Keyword

nonn,cons,easy

Author

Paolo Xausa, Nov 20 2024

Status

approved