A102769 -id:A102769 - cp's OEIS frontend

A377805 Decimal expansion of the volume of a snub dodecahedron with unit edge length.

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

Offset: 2

Paolo Xausa, Nov 09 2024

			37.616649962733362975777673671302714340355289873...

Eric Weisstein's World of Mathematics, Snub Dodecahedron.
Wikipedia, Snub dodecahedron.
Index entries for algebraic numbers, degree 12.

Cf. A377804 (surface area), A377806 (circumradius), A377807 (midradius).
Cf. A102769 (analogous for a regular dodecahedron).
Cf. A001622, A090550, A104457, A134946, A377849.

First[RealDigits[((3*GoldenRatio + 1)*#*(# + 1) - GoldenRatio/6 - 2)/Sqrt[3*#^2 - GoldenRatio^2], 10, 100]] & [Root[#^3 + 2*#^2 - GoldenRatio^2 &, 1]] (* or *)
First[RealDigits[PolyhedronData["SnubDodecahedron", "Volume"], 10, 100]]

Equals ((3*phi + 1)*xi*(xi + 1) - phi/6 - 2)/sqrt(3*xi^2 - phi^2) = (A090550*xi*(xi + 1) - A134946 - 2)/sqrt(3*xi^2 - A104457), where phi = A001622 and xi = A377849.

Equals the largest real root of 2176782336*x^12 - 3195335070720*x^10 + 162223191936000*x^8 + 1030526618040000*x^6 + 6152923794150000*x^4 - 182124351550575000*x^2 + 187445810737515625.

A385802 Decimal expansion of the volume of a parabiaugmented dodecahedron with unit edge.

Original entry on oeis.org

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

Offset: 1

Paolo Xausa, Jul 09 2025

The parabiaugmented dodecahedron is Johnson solid J_59.

Also the volume of a metabiaugmented dodecahedron (Johnson solid J_60) with unit edge.

			8.266124625416281110083485059340673098307800325954...

Paolo Xausa, Table of n, a(n) for n = 1..10000
Wikipedia, Parabiaugmented dodecahedron.

Cf. A385803 (surface area).

Cf. A002163, A102769, A179552, A385695, A385804.

First[RealDigits[(25 + 11*Sqrt[5])/6, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["J59", "Volume"], 10, 100]]

Equals (25 + 11*sqrt(5))/6 = (25 + 11*A002163)/6.
Equals A102769 + 2*A179552.
Equals the largest root of 9*x^2 - 75*x + 5.

A385804 Decimal expansion of the volume of a triaugmented dodecahedron with unit edge.

Original entry on oeis.org

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

Offset: 1

Paolo Xausa, Jul 09 2025

The triaugmented dodecahedron is Johnson solid J_61.

			8.56762745781210568076720062887114294145115942427...

Paolo Xausa, Table of n, a(n) for n = 1..10000
Wikipedia, Triaugmented dodecahedron.

Cf. A385805 (surface area).

Cf. A010499, A102769, A179552, A377697, A385695, A385802.

First[RealDigits[5/8*(7 + Sqrt[45]), 10, 100]] (* or *)
First[RealDigits[PolyhedronData["J61", "Volume"], 10, 100]]

Equals (5/8)*(7 + 3*sqrt(5)) = (5/8)*(7 + A010499).
Equals A102769 + 3*A179552.
Equals the largest root of 16*x^2 - 140*x + 25.
Equals A377697^2. - Hugo Pfoertner, Jul 13 2025

A363438 Decimal expansion of the volume of the regular dodecahedron inscribed in the unit-radius sphere.

Original entry on oeis.org

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

Offset: 1

Amiram Eldar, Jun 02 2023

			2.78516386312262296729255491273594698789932177207633...

Eric Weisstein's World of Mathematics, Regular Dodecahedron.
Wikipedia, Regular dodecahedron.
Index entries for algebraic numbers, degree 4.

Cf. A118273 (cube), A122553 (regular octahedron), A339259 (regular icosahedron), A363437 (regular tetrahedron).
Cf. A001622.
Other constants related to the regular dodecahedron: A102769, A131595, A179296, A232810, A237603, A239798, A341906.

RealDigits[(2*(5 + Sqrt[5]))/(3*Sqrt[3]), 10, 120][[1]]

2*sqrt(5+sqrt(5))/sqrt(27) \\ Charles R Greathouse IV, Feb 07 2025

Equals 2*sqrt(5+sqrt(5))/(3*sqrt(3)).
Equals 4*(phi+2)/(3*sqrt(3)), where phi is the golden ratio (A001622).
Equals A102769 / A179296 ^ 3.

A374771 Decimal expansion of the volume of the sphere inscribed in a regular dodecahedron with unit edge.

Original entry on oeis.org

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

Offset: 1

Paolo Xausa, Jul 19 2024

			5.78333595039657417842182321041033675553722324626...

Paolo Xausa, Table of n, a(n) for n = 1..10000
Wikipedia, Regular dodecahedron.

Cf. A000796, A001622, A019699, A102769, A237603 (radius), A374772.

First[RealDigits[Pi*Sqrt[1525 + 682*Sqrt[5]]/30, 10, 100]]

Equals (4/3)*Pi*A237603^3 = 10*A019699*A237603^3.
Equals (1/30)*Pi*sqrt(1525 + 682*sqrt(5)).
Equals (Pi/6)*A001622^6/((3 - A001622)^(3/2)).
Equals A102769*A374772.

A385695 Decimal expansion of the volume of an augmented dodecahedron with unit edge.

Original entry on oeis.org

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

Offset: 1

Paolo Xausa, Jul 08 2025

The augmented dodecahedron is Johnson solid J_58.

			7.9646217930204565393997694898102032551644412276373...

Paolo Xausa, Table of n, a(n) for n = 1..10000
Wikipedia, Augmented dodecahedron.

Cf. A385696 (surface area).

Cf. A002163, A102769, A179552, A385802, A385804.

First[RealDigits[(95 + 43*Sqrt[5])/24, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["J58", "Volume"], 10, 100]]

Equals (95 + 43*sqrt(5))/24 = (95 + 43*A002163)/24.
Equals A102769 + A179552.
Equals the largest root of 144*x^2 - 1140*x - 55.

A341906 Decimal expansion of the moment of inertia of a solid regular dodecahedron with a unit mass and a unit edge length.

Original entry on oeis.org

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

Offset: 0

Amiram Eldar, Jun 04 2021

The moments of inertia of the five Platonic solids were apparently first calculated by the Canadian physicist John Satterly (1879-1963) in 1957.
The moment of inertia of a solid regular dodecahedron with a uniform mass density distribution, mass M, and edge length L is I = c*M*L^2, where c is this constant.
The corresponding values of c for the other Platonic solids are:
Tetrahedron: 1/20 (= A020761/10).
Octahedron: 1/10 (= A000007).
Cube: 1/6 (= A020793).
Icosahedron: (3 + sqrt(5))/20 (= A104457/10).

			0.60735550374163932719985924360173257727394705341616...

P. K. Aravind, Gravitational collapse and moment of inertia of regular polyhedral configurations, American Journal of Physics, Vol. 59, No. 7 (1991), pp. 647-652.
Frédéric Perrier, Moments of inertia of Archimedean solids, 2015.
John Satterly, Moments of Inertia about Selected Axes of Regular Polygons, Right Pyramids on Regular Polygonal Bases, and of the Platonic and Some Archimedian Polyhedra, American Journal of Physics, Vol. 25, No. 7 (1957), pp. 489-490.
John Satterly, The Moments of Inertia of Some Polyhedra, The Mathematical Gazette, Vol. 42, No. 339 (1958), pp. 11-13.
Wikipedia, List of moments of inertia.
Wikipedia, Moment of inertia.
Wikipedia, Regular dodecahedron.
Index entries for sequences related to moment of inertia.

Cf. A000007, A001622, A020761, A020793, A104457.

Other constants related to the regular dodecahedron: A102769, A131595, A179296, A232810, A237603, A239798.

RealDigits[(95 + 39*Sqrt[5])/300, 10, 100][[1]]

Equals (95 + 39*sqrt(5))/300.

Equals (28 + 39*phi)/150, where phi is the golden ratio (A001622).

A364896 Decimal expansion of the 4-volume of the unit regular 120-cell.

Original entry on oeis.org

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

Offset: 3

Jianing Song, Aug 12 2023

Decimal expansion of (1575+705*sqrt(5))/4.

			Equals 787.85698103433793399211...

Polytope Wiki, Hecatonicosachoron
Wikipedia, 120-cell

Decimal expansion of 4-volumes: A364895 (5-cell), A000007 = 1 (8-cell or tesseract), A020793 = 1/6 (16-cell), A000038 = 2 (24-cell), this sequence (120-cell), A364897 (600-cell).

Cf. A102769 (decimal expansion of the volume of the unit regular dodecahedron).

First[RealDigits[(1575 + 705*Sqrt[5])/4, 10, 100]] (* Paolo Xausa, Jun 12 2024 *)

PARI
```
(1575+705*sqrt(5))/4
```

cp's OEIS Frontend

A377805 Decimal expansion of the volume of a snub dodecahedron with unit edge length.

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A385802 Decimal expansion of the volume of a parabiaugmented dodecahedron with unit edge.

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A385804 Decimal expansion of the volume of a triaugmented dodecahedron with unit edge.

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A363438 Decimal expansion of the volume of the regular dodecahedron inscribed in the unit-radius sphere.

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A374771 Decimal expansion of the volume of the sphere inscribed in a regular dodecahedron with unit edge.

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A385695 Decimal expansion of the volume of an augmented dodecahedron with unit edge.

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A341906 Decimal expansion of the moment of inertia of a solid regular dodecahedron with a unit mass and a unit edge length.

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A364896 Decimal expansion of the 4-volume of the unit regular 120-cell.

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