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.

Previous Showing 11-15 of 15 results.

A179592 Decimal expansion of the circumradius of pentagonal cupola with edge length 1.

Original entry on oeis.org

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

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Author

Keywords

Comments

Pentagonal cupola: 15 vertices, 25 edges, and 12 faces.

Examples

			2.232950509415690049500415383249682772934080730579181647457441260...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[Sqrt[11+4*Sqrt[5]]/2,200]]

Formula

Digits of sqrt(11+4*sqrt(5))/2.

A384286 Decimal expansion of the surface area of a gyroelongated pentagonal rotunda with unit edge.

Original entry on oeis.org

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

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Author

Paolo Xausa, May 30 2025

Keywords

Comments

The gyroelongated pentagonal rotunda is Johnson solid J_25.

Examples

			31.00745430323851474443564586571797490853203978248...
		

Crossrefs

Programs

  • Mathematica
    First[RealDigits[(15*Sqrt[3] + Sqrt[650 + 290*Sqrt[5]])/2, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J25", "SurfaceArea"], 10, 100]]

Formula

Equals (15*sqrt(3) + sqrt(650 + 290*sqrt(5)))/2 = (15*A002194 + sqrt(650 + 290*A002163))/2.
Equals the largest root of 256*x^8 - 339200*x^6 + 98924000*x^4 - 9264250000*x^2 + 176295015625.

A179639 Decimal expansion of the volume of gyroelongated pentagonal pyramid with edge length 1.

Original entry on oeis.org

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

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Author

Keywords

Comments

Gyroelongated pentagonal pyramid: 11 vertices,25 edges,and 16 faces.

Examples

			1.88019215822908780282010679244089525495689855152098881326825313369561...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[(25+9*Sqrt[5])/24,200]]

Formula

Digits of (25+9*sqrt(5))/24.

A179640 Decimal expansion of the surface area of gyroelongated pentagonal pyramid with edge length 1.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

Gyroelongated pentagonal pyramid: 11 vertices, 25 edges, and 16 faces.

Examples

			8.21566792897225677348693575803563097544289387179912568441637087996861...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[Sqrt[5/2*(70+Sqrt[5]+3*Sqrt[75+30*Sqrt[5]])]/2,200]]

Formula

Digits of sqrt(5/2*(70+sqrt(5)+3*sqrt(75+30*sqrt(5))))/2.

A386852 Decimal expansion of the dihedral angle, in radians, between the pentagonal face and a triangular face in a pentagonal pyramid with equal edges (Johnson solid J_2).

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Aug 05 2025

Keywords

Comments

Also the dihedral angle, in radians, between the 10-gonal face and a triangular face in a pentagonal cupola (Johnson solid J_5)

Examples

			0.65235813978436818599539063164382257436530791996...
		

Crossrefs

Cf. A179552 (J_2 volume), A179553 (J_2 surface area).
Cf. A179590 (J_5 volume), A179591 (J_5 surface area).

Programs

  • Mathematica
    First[RealDigits[ArcSec[Sqrt[15 - 6*Sqrt[5]]], 10, 100]] (* or *)
    First[RealDigits[Min[PolyhedronData["J2", "DihedralAngles"]], 10, 100]]
  • PARI
    acos(sqrt((5+2*sqrt(5))/15)) \\ Charles R Greathouse IV, Aug 19 2025

Formula

Equals arcsec(sqrt(15 - 6*sqrt(5))) = arcsec(sqrt(15 - 6*A002163)).
Equals arccos(sqrt((5 + 2*sqrt(5))/15)) = arccos(sqrt((5 + A010476)/15)).
Previous Showing 11-15 of 15 results.