cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A378389 Decimal expansion of the dihedral angle, in radians, between any two adjacent faces in a tetrakis hexahedron.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Nov 27 2024

Keywords

Comments

The tetrakis hexahedron is the dual polyhedron of the truncated octahedron.

Examples

			2.498091544796508851659834154562180246155658808...
		

Crossrefs

Cf. A378388 (surface area), A374359 (volume - 1), A010532 (inradius*10), A179587 (midradius + 1).
Cf. A156546 and A195698 (dihedral angles of a truncated octahedron), A195729.

Programs

  • Mathematica
    First[RealDigits[ArcCos[-4/5], 10, 100]] (* or *)
    First[RealDigits[First[PolyhedronData["TetrakisHexahedron", "DihedralAngles"]], 10, 100]]

Formula

Equals arccos(-4/5).
Equals 2*A195729. - Amiram Eldar, Nov 27 2024

A382004 Decimal expansion of the isoperimetric quotient of a tetrakis hexahedron.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Mar 17 2025

Keywords

Comments

For the definition of isoperimetric quotient of a solid, references and links, see A381684.

Examples

			0.84297776772488716717876495718458737593598110244806...
		

Crossrefs

Cf. A378388 (surface area), A374359 (volume - 1).

Programs

  • Mathematica
    First[RealDigits[3*Pi/5/Sqrt[5], 10, 100]]

Formula

Equals 36*Pi*(A374359 + 1)^2/(A378388^3).
Equals 3*Pi/(5*sqrt(5)) = (3/5)*A000796/A002163.
Showing 1-2 of 2 results.