A380796 Decimal expansion of the largest acute vertex angle, in radians, in a pentakis dodecahedron face.

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

Offset

1,3

Comments

A pentakis dodecahedron face is an acute isoscele triangle with the smallest angles being A380795 and the largest angle being this constant.

Links

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

Eric Weisstein's World of Mathematics, Pentakis Dodecahedron.

Wikipedia, Pentakis dodecahedron.

Formula

Equals arccos((9*A001622 - 8)/18).

Equals Pi - 2*A380795.

Example

1.1976226087563797890813284298421039858218935910...

Mathematica

First[RealDigits[ArcCos[(9*GoldenRatio - 8)/18], 10, 100]]

Crossrefs

Cf. A001622, A379132, A379133, A379135, A379136, A380795.

Sequence in context: A021839 A349009 A094131 * A021510 A199272 A390075

Adjacent sequences: A380793 A380794 A380795 * A380797 A380798 A380799

Keyword

nonn,cons,easy

Author

Paolo Xausa, Feb 04 2025

Status

approved