A289502 Decimal expansion of the mean width of the regular tetrahedron of unit edge length.

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

Offset

0,1

Links

Table of n, a(n) for n=0..86.

Steven R. Finch, Mean width of a regular simplex, arxiv:1111.4976 [math.MG] (2016), E(w_3).

Formula

Equals A156546*A093582.

Maple

x := 3*arccos(-1/3)/2/Pi ; evalf(%) ;

Mathematica

RealDigits[3 ArcCos[-1/3]/(2*Pi), 10, 87][[1]] (* Indranil Ghosh, Jul 08 2017 *)

Prog

(PARI) 3*acos(-1/3)/(2*Pi) \\ Amiram Eldar, May 05 2026

Crossrefs

Cf. A156546, A093582.

Cf. this constant (regular tetrahedron), A152623 (cube), A395731 (regular octahedron), A395732 (regular dodecahedron), A395733 (regular icosahedron).

Sequence in context: A010166 A186116 A242627 * A010165 A177273 A176521

Adjacent sequences: A289499 A289500 A289501 * A289503 A289504 A289505

Keyword

cons,nonn

Author

R. J. Mathar, Jul 07 2017

Status

approved