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 1-7 of 7 results.

A378393 Decimal expansion of the midradius of a deltoidal icositetrahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Nov 30 2024

Keywords

Comments

The deltoidal icositetrahedron is the dual polyhedron of the (small) rhombicuboctahedron.

Examples

			1.5606601717798212866012665431572735589272539065327...
		

Crossrefs

Cf. A378390 (surface area), A378391 (volume), A378392 (inradius), A378394 (dihedral angle).
Cf. A285871 (midradius of a (small) rhombicuboctahedron with unit edge).

Programs

  • Mathematica
    First[RealDigits[(2 + Sqrt[18])/4, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["DeltoidalIcositetrahedron", "Midradius"], 10, 100]]

Formula

Equals (2 + 3*sqrt(2))/4 = (2 + A010474)/4.

A378207 Decimal expansion of the midradius of a triakis tetrahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Nov 21 2024

Keywords

Comments

The triakis tetrahedron is the dual polyhedron of the truncated tetrahedron.

Examples

			0.589255650988789603667370301754040866070696614740...
		

Crossrefs

Cf. A378204 (surface area), A378205 (volume), A378206 (inradius), A378208 (dihedral angle).
Cf. A093577 (midradius of a truncated tetrahedron with unit edge).
Cf. A010524.

Programs

  • Mathematica
    First[RealDigits[5/Sqrt[72], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["TriakisTetrahedron", "Midradius"], 10, 100]]
  • PARI
    5/sqrt(72) \\ Charles R Greathouse IV, Feb 11 2025

Formula

Equals 5/(6*sqrt(2)) = 5/A010524.

A377275 Decimal expansion of the volume of a truncated tetrahedron with unit edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Oct 23 2024

Keywords

Examples

			2.7105759945484321768699033880685879839252044278...
		

Crossrefs

Cf. A377274 (surface area), A377276 (circumradius), A093577 (midradius), A377277 (Dehn invariant).
Cf. A020829 (analogous for a regular tetrahedron).
Cf. A002193.

Programs

  • Mathematica
    First[RealDigits[23/12*Sqrt[2], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["TruncatedTetrahedron", "Volume"], 10, 100]]

Formula

Equals (23/12)*sqrt(2) = (23/12)*A002193.

A377274 Decimal expansion of the surface area of a truncated tetrahedron with unit edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Oct 23 2024

Keywords

Examples

			12.12435565298214105469212439054110656859963677667...
		

Crossrefs

Cf. A377275 (volume), A377276 (circumradius), A093577 (midradius), A377277 (Dehn invariant).
Cf. A002194 (analogous for a regular tetrahedron).

Programs

  • Mathematica
    First[RealDigits[7*Sqrt[3], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["TruncatedTetrahedron", "SurfaceArea"], 10, 100]]

Formula

Equals 7*sqrt(3) = 7*A002194.

A377276 Decimal expansion of the circumradius of a truncated tetrahedron with unit edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Oct 23 2024

Keywords

Examples

			1.17260393995585738864140752838611657014705708835...
		

Crossrefs

Cf. A377274 (surface area), A377275 (volume), A093577 (midradius), A377277 (Dehn invariant).
Cf. A187110 (analogous for a regular tetrahedron).
Cf. A010478.

Programs

  • Mathematica
    First[RealDigits[Sqrt[22]/4, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["TruncatedTetrahedron", "Circumradius"], 10, 100]]

Formula

Equals sqrt(22)/4 = A010478/4.

A243309 Decimal expansion of DeVicci's tesseract constant.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 03 2014

Keywords

Comments

This "tesseract" constant is the edge length of the largest 3-dimensional cube that can be inscribed within a unit 4-dimensional cube.
From Amiram Eldar, May 29 2021: (Start)
Named by Finch (2003) after Kay R. Pechenick DeVicci Shultz.
The problem was apparently first posed by Gardner (1966). According to Gardner (2001), he had received the correct answers to the problem from Eugen I. Bosch (1966), G. de Josselin de Jong (1971), Hermann Baer (1974) and Kay R. Pechenick (1983). (End)

Examples

			1.00743475688427937609825359523109914192569...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.14 DeVicci's tesseract constant, p. 524.
  • Martin Gardner, Is It Possible to Visualize a Four-Dimensional Figure?, Mathematical Games, Sci. Amer., Vol. 215, No. 5, (Nov. 1966), pp. 138-143.
  • Martin Gardner, Mathematical Carnival: A New Round-Up of Tantalizers and Puzzles from Scientific American, New York: Vintage Books, 1977, Chapter 4, "Hypercubes", pp. 41-54.
  • Martin Gardner, The Colossal Book of Mathematics, New York, London: W. W. Norton & Co., 2001, Chapter 13, "Hypercubes", pp. 162-174.

Crossrefs

Cf. A093577.

Programs

  • Mathematica
    Root[4*x^8 - 28*x^6 - 7*x^4 + 16*x^2 + 16, x, 3] // RealDigits[#, 10, 103]& // First
  • PARI
    polrootsreal(4*x^8-28*x^6-7*x^4+16*x^2+16)[3] \\ Charles R Greathouse IV, Apr 07 2016
    
  • PARI
    sqrt(polrootsreal(Pol([4,-28,-7,16,16]))[1]) \\ Charles R Greathouse IV, Apr 07 2016

Formula

Positive root of the polynomial 4*x^8 - 28*x^6 - 7*x^4 + 16*x^2 + 16.

A243313 Decimal expansion of a 5-dimensional analog of DeVicci's tesseract constant.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Jun 03 2014

Keywords

Comments

This constant is the edge length of the largest 3-dimensional cube that can be inscribed within a unit 5-dimensional cube.
Also, the smallest positive root in x^4 - 22*x^2 + 25 = 0.

Examples

			1.0963763171773128040759311069135237901965384969435155182975524965...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.14 DeVicci's tesseract constant, p. 525.

Crossrefs

Programs

  • Mathematica
    RealDigits[Sqrt[11-4*Sqrt[6]], 10, 104] // First
  • PARI
    2*sqrt(2)-sqrt(3) \\ Stefano Spezia, Dec 24 2024

Formula

Equals sqrt(11-4*sqrt(6)) = 2*sqrt(2)-sqrt(3).
Showing 1-7 of 7 results.