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 1-6 of 6 results.

A379132 Decimal expansion of the surface area of a pentakis dodecahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Dec 16 2024

Keywords

Comments

The pentakis dodecahedron is the dual polyhedron of the truncated icosahedron.

Examples

			27.93524960070079310581019127996368070525778610907...
		

Crossrefs

Cf. A379133 (volume), A379134 (inradius), A379135 (midradius), A379136 (dihedral angle).
Cf. A377750 (surface area of a truncated icosahedron with unit edge length).
Cf. A002163.

Programs

  • Mathematica
    First[RealDigits[5/3*Sqrt[(421 + 63*Sqrt[5])/2], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["PentakisDodecahedron", "SurfaceArea"], 10, 100]]
  • PARI
    sqrt((421 + 63*sqrt(5))/2)*5/3 \\ Charles R Greathouse IV, Feb 05 2025

Formula

Equals (5/3)*sqrt((421 + 63*sqrt(5))/2) = (5/3)*sqrt((421 + 63*A002163)/2).

A379133 Decimal expansion of the volume of a pentakis dodecahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Dec 16 2024

Keywords

Comments

The pentakis dodecahedron is the dual polyhedron of the truncated icosahedron.

Examples

			13.458569366318714223642964127539153595279924859762...
		

Crossrefs

Cf. A379132 (surface area), A379134 (inradius), A379135 (midradius), A379136 (dihedral angle).
Cf. A377751 (volume of a truncated icosahedron with unit edge length).
Cf. A002163.

Programs

  • Mathematica
    First[RealDigits[5/36*(41 + 25*Sqrt[5]), 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["PentakisDodecahedron", "Volume"], 10, 100]]
  • PARI
    (41 + 25*sqrt(5))*5/36 \\ Charles R Greathouse IV, Feb 05 2025

Formula

Equals (5/36)*(41 + 25*sqrt(5)) = (5/36)*(41 + 25*A002163).

A379135 Decimal expansion of the midradius of a pentakis dodecahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Dec 17 2024

Keywords

Comments

The pentakis dodecahedron is the dual polyhedron of the truncated icosahedron.

Examples

			1.4756836610416140907689600838494857255268212565695...
		

Crossrefs

Cf. A379132 (surface area), A379133 (volume), A379134 (inradius), A379136 (dihedral angle).
Cf. A205769 (midradius + 1 of a truncated icosahedron with unit edge length).
Cf. A010499.

Programs

  • Mathematica
    First[RealDigits[(11 + Sqrt[45])/12, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["PentakisDodecahedron", "Midradius"], 10, 100]]
  • PARI
    (11 + 3*sqrt(5))/12 \\ Charles R Greathouse IV, Feb 05 2025

Formula

Equals (11 + 3*sqrt(5))/12 = (11 + A010499)/12.

A379134 Decimal expansion of the inradius of a pentakis dodecahedron with unit shorter edge length.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Dec 17 2024

Keywords

Comments

The pentakis dodecahedron is the dual polyhedron of the truncated icosahedron.

Examples

			1.4453319256522148283158512491020811977238711778430...
		

Crossrefs

Cf. A379132 (surface area), A379133 (volume), A379135 (midradius), A379136 (dihedral angle).
Cf. A002163.

Programs

  • Mathematica
    First[RealDigits[Sqrt[477/436 + 97*Sqrt[5]/218], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["PentakisDodecahedron", "Inradius"], 10, 100]]
  • PARI
    sqrt(477/436 + 97*sqrt(5)/218) \\ Charles R Greathouse IV, Feb 05 2025

Formula

Equals sqrt(477/436 + 97*sqrt(5)/218) = sqrt(477/436 + 97*A002163/218).
Equals the largest root of 1744*x^4 - 3816*x^2 + 361.

A380795 Decimal expansion of the smallest acute vertex angles, in radians, in a pentakis dodecahedron face.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Feb 04 2025

Keywords

Comments

A pentakis dodecahedron face is an acute isoscele triangle with the smallest angles being this constant and the largest angle being A380796.

Examples

			0.97198502241670672469065747671869944918763790417527...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[ArcCos[(5 - GoldenRatio)/6], 10, 100]]

Formula

Equals arccos((5 - A001622)/6).
Equals (Pi - A380796)/2.

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

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Feb 04 2025

Keywords

Comments

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

Examples

			1.1976226087563797890813284298421039858218935910...
		

Crossrefs

Programs

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

Formula

Equals arccos((9*A001622 - 8)/18).
Equals Pi - 2*A380795.
Showing 1-6 of 6 results.