A378390 Decimal expansion of the surface area of a deltoidal icositetrahedron with unit shorter edge length.

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

Offset: 2

Author

Paolo Xausa, Nov 29 2024

Keywords

• nonn
• cons
• easy

Comments

The deltoidal icositetrahedron is the dual polyhedron of the (small) rhombicuboctahedron.

Examples

			30.694895724031009590770314784050673387965107463161...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 2..10000
• Eric Weisstein's World of Mathematics, Deltoidal Icositetrahedron.
• Wikipedia, Deltoidal icositetrahedron.
• Index entries for algebraic numbers, degree 4.

Crossrefs

Cf. A378391 (volume), A378392 (inradius), A378393 (midradius), A378394 (dihedral angle).

Cf. A343964 (surface area of a (small) rhombicuboctahedron with unit edge).

Cf. A010466.

Programs

Mathematica

First[RealDigits[6*Sqrt[29 - Sqrt[8]], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["DeltoidalIcositetrahedron", "SurfaceArea"], 10, 100]]

Formula

Equals 6*sqrt(29 - 2*sqrt(2)) = 6*sqrt(29 - A010466).