A380941 Decimal expansion of the middle vertex angle, in radians, in a disdyakis triacontahedron face.

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

Offset: 1

Author

Paolo Xausa, Feb 08 2025

Keywords

• nonn
• cons
• easy

Comments

A disdyakis triacontahedron face is a scalene triangle with three acute angles.

Examples

			1.016443446896330150160097551517069643637928892906...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000
• Wikipedia, Disdyakis triacontahedron.

Crossrefs

Cf. A380940 (smallest face angle), A380942 (largest face angle).

Cf. A001622, A379388, A379708, A379709, A379710, A379711.

Programs

Mathematica

First[RealDigits[ArcCos[(17 - 4*GoldenRatio)/20], 10, 100]]

Formula

Equals arccos((17 - 4*A001622)/20).

Equals Pi - A380940 - A380942.