A380704 Decimal expansion of the acute vertex angles, in radians, in a deltoidal icositetrahedron face.

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

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Wikipedia, Deltoidal icositetrahedron.

Formula

Equals arccos(1/2 - sqrt(2)/4) = arccos(1/2 - A020765).

Equals (2*Pi - A380705)/3.

Example

1.4238211361313915494455573566669046848857979902951...

Mathematica

First[RealDigits[ArcCos[1/2 - Sqrt[2]/4], 10, 100]]

Crossrefs

Cf. A380705 (obtuse face angle).

Cf. A020765, A378390, A378391, A378392, A378393, A378394.

Sequence in context: A143054 A195953 A016512 * A201651 A357463 A349119

Adjacent sequences: A380701 A380702 A380703 * A380705 A380706 A380708

Keyword

nonn,cons,easy

Author

Paolo Xausa, Jan 31 2025

Status

approved