A363437 Decimal expansion of the volume of the regular tetrahedron inscribed in the unit-radius sphere.

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

Offset: 0

Author

Amiram Eldar, Jun 02 2023

Keywords

• nonn
• cons

Examples

			0.51320023927966734623035447155729551613120155668455...
		

Links

• Eric Weisstein's World of Mathematics, Regular Tetrahedron.
• Wikipedia, Tetrahedron: Regular tetrahedron.
• Index entries for algebraic numbers, degree 2.

Crossrefs

Cf. A118273 (cube), A122553 (regular octahedron), A339259 (regular icosahedron), A363438 (regular dodecahedron).

Other constants related to the regular tetrahedron: A020781, A020829, A137914, A156546, A187110, A210974, A232812, A236555.

Programs

Mathematica

RealDigits[8/(9*Sqrt[3]), 10, 120][[1]]

PARI

8/9/sqrt(3) \\ Charles R Greathouse IV, Feb 07 2025

Formula

Equals 8/(9*sqrt(3)).

Equals A118273 / 3.

Equals A020829 / A187110 ^ 3.