A379389 Decimal expansion of the dihedral angle, in radians, between any two adjacent faces in a deltoidal hexecontahedron.

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

Offset: 1

Author

Paolo Xausa, Dec 23 2024

Keywords

• nonn
• cons
• easy

Comments

The deltoidal hexecontahedron is the dual polyhedron of the (small) rhombicosidodecahedron.

Examples

			2.6899252342065763400728815146316168300353303724921...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Deltoidal Hexecontahedron.
• Wikipedia, Deltoidal hexecontahedron.

Crossrefs

Cf. A379385 (surface area), A379386 (volume), A379387 (inradius), A379388 (midradius).

Cf. A377995 and A377996 (dihedral angles of a (small) rhombicosidodecahedron).

Cf. A002163.

Programs

Mathematica

First[RealDigits[ArcCos[-(19 + 8*Sqrt[5])/41], 10, 100]] (* or *)
First[RealDigits[First[PolyhedronData["DeltoidalHexecontahedron", "DihedralAngles"]], 10, 100]]

Formula

Equals arccos(-(19 + 8*sqrt(5))/41) = arccos(-(19 + 8*A002163)/41).