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.

A384283 Decimal expansion of the volume of a gyroelongated pentagonal cupola with unit edge.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, May 26 2025

Keywords

Comments

The gyroelongated pentagonal cupola is Johnson solid J_24.

Examples

			9.07333319388018799314998398101816272215313393060...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[(5 + Sqrt[80] + 5*Sqrt[2*(Sqrt[650 + 290*Sqrt[5]] - Sqrt[5] - 1)])/6, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J24", "Volume"], 10, 100]]
  • PARI
    (5 + 4*sqrt(5) + 5*sqrt(2*(sqrt(650 + 290*sqrt(5)) - sqrt(5) - 1)))/6 \\ Charles R Greathouse IV, Aug 19 2025

Formula

Equals (5 + 4*sqrt(5) + 5*sqrt(2*(sqrt(650 + 290*sqrt(5)) - sqrt(5) - 1)))/6 = (5 + A010532 + 5*sqrt(2*(sqrt(650 + 290*A002163) - A002163 - 1)))/6.
Equals the largest real root of 1679616*x^8 - 11197440*x^7 + 27060480*x^6 + 35769600*x^5 - 4456749600*x^4 - 10714248000*x^3 + 3828402000*x^2 + 13859430000*x + 5340175625.

A384140 Decimal expansion of the volume of an elongated pentagonal bipyramid with unit edge.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, May 20 2025

Keywords

Comments

The elongated pentagonal bipyramid is Johnson solid J_16.

Examples

			2.32348306538061606412644311644954928569409236664...
		

Crossrefs

Cf. A384141 (surface area).

Programs

  • Mathematica
    First[RealDigits[(5 + Sqrt[5] + 3*Sqrt[25 + 10*Sqrt[5]])/12, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J16", "Volume"], 10, 100]]

Formula

Equals (5 + sqrt(5) + 3*sqrt(25 + 10*sqrt(5)))/12 = (5 + A002163 + 3*sqrt(25 + 10*A002163))/12.
Equals the largest root of 20736*x^4 - 34560*x^3 - 44640*x^2 + 27600*x + 6025.

A384144 Decimal expansion of the volume of an elongated pentagonal cupola with unit edge.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, May 22 2025

Keywords

Comments

The elongated pentagonal cupola is Johnson solid J_20.

Examples

			10.0182541612713266373651755525797920503105009319...
		

Crossrefs

Cf. A179591 (surface area - 10).

Programs

  • Mathematica
    First[RealDigits[(5 + Sqrt[80] + 15*Sqrt[5 + Sqrt[20]])/6, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J20", "Volume"], 10, 100]]

Formula

Equals (5 + 4*sqrt(5) + 15*sqrt(5 + 2*sqrt(5)))/6 = (5 + A010532 + 15*sqrt(5 + A010476))/6.
Equals the largest root of 324*x^4 - 1080*x^3 - 20340*x^2 - 18600*x + 49975.

A384213 Decimal expansion of the volume of an elongated pentagonal rotunda with unit edge.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, May 23 2025

Keywords

Comments

The elongated pentagonal rotunda is Johnson solid J_21.

Examples

			14.611971811062835576338722470794915893557631368294...
		

Crossrefs

Cf. A179637 (surface area - 10).

Programs

  • Mathematica
    First[RealDigits[(45 + 17*Sqrt[5] + 30*Sqrt[5 + Sqrt[20]])/12, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J21", "Volume"], 10, 100]]

Formula

Equals (45 + 17*sqrt(5) + 30*sqrt(5 + 2*sqrt(5)))/12 = (45 + 17*A002163 + 30*sqrt(5 + A010476))/12.
Equals the largest real root of 1296*x^4 - 19440*x^3 + 2340*x^2 + 70200*x + 43525.

A384285 Decimal expansion of the volume of a gyroelongated pentagonal rotunda with unit edge.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, May 29 2025

Keywords

Comments

The gyroelongated pentagonal rotunda is Johnson solid J_25.

Examples

			13.667050843671696932123530899233286565400264...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[(45 + 17*# + 10*Sqrt[2*(Sqrt[650 + 290*#] - # - 1)])/12 & [Sqrt[5]], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J25", "Volume"], 10, 100]]

Formula

Equals (45 + 17*sqrt(5) + 10*sqrt(2*(sqrt(650 + 290*sqrt(5)) - sqrt(5) - 1)))/12 = (45 + 17*A002163 + 10*sqrt(2*(sqrt(650 + 290*A002163) - A002163 - 1)))/12.
Equals the largest real root of 1679616*x^8 - 50388480*x^7 + 603262080*x^6 - 3520972800*x^5 + 5215460400*x^4 + 4128624000*x^3 - 8894943000*x^2 + 3881385000*x - 424924375.

A384139 Decimal expansion of the volume of an elongated triangular bipyramid with unit edges.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, May 20 2025

Keywords

Comments

The elongated triangular bipyramid is Johnson solid J_14.
Also the volume of an augmented triangular prism (Johnson solid J_49) with unit edges. - Paolo Xausa, Aug 04 2025

Examples

			0.66871496228773516484880970607808443816397995934875...
		

Crossrefs

Cf. A165663 (surface area - 2).

Programs

  • Mathematica
    First[RealDigits[(Sqrt[8] + Sqrt[27])/12, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J14", "Volume"], 10, 100]]

Formula

Equals (2*sqrt(2) + 3*sqrt(3))/12 = (A010466 + A010482)/12.
Equals the largest root of 20736*x^4 - 10080*x^2 + 361.

A387147 Decimal expansion of the dihedral angle, in radians, between triangular and square faces in an elongated pentagonal pyramid (Johnson solid J_9).

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Aug 18 2025

Keywords

Comments

Also one of the dihedral angles, in radians, in an elongated pentagonal bipyramid, elongated pentagonal cupola, elongated pentagonal orthobicupola, elongated pentagonal gyrobicupola, elongated pentagonal orthocupolarotunda and elongated pentagonal gyrocupolarotunda (Johnson solids J_16, J_20, J_38, J_39, J_40 and J_41, respectively).

Examples

			2.2231544665792648052267123232835740164638926196505...
		

Crossrefs

Cf. A384138 (J_9 volume).
Cf. other J_9 dihedral angles: A019669, A228719, A236367.
Cf. A010476.

Programs

  • Mathematica
    First[RealDigits[ArcCos[-Sqrt[(10 - Sqrt[20])/15]], 10, 100]] (* or *)
    First[RealDigits[RankedMax[Union[PolyhedronData["J9", "DihedralAngles"]], 2], 10, 100]]
  • PARI
    acos(-sqrt((10 - sqrt(20))/15)) \\ Charles R Greathouse IV, Aug 19 2025

Formula

Equals arccos(-sqrt((10 - 2*sqrt[5])/15)) = arccos(-sqrt((10 - A010476)/15)).
Showing 1-7 of 7 results.