A381695 Decimal expansion of the isoperimetric quotient of a truncated icosidodecahedron (great rhombicosidodecahedron).

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

Offset

0,1

Comments

For the definition of isoperimetric quotient of a solid, references and links, see A381684.

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

Index entries for transcendental numbers

Formula

Equals 36*Pi*A377797^2/(A377796^3).

Equals (Pi/30)*(861 + 380*sqrt(5))/((1 + sqrt(3) + sqrt(5 + 2*sqrt(5)))^3) = (A000796/30)*(861 + 380*A002163)/((1 + A002194 + sqrt(5 + A010476))^3).

Example

0.9135559084097273251197488307206577890586199166868...

Mathematica

First[RealDigits[Pi/30*(861 + 380*Sqrt[5])/(1 + Sqrt[3] + Sqrt[5 + Sqrt[20]])^3, 10, 100]]

Crossrefs

Cf. A377796 (surface area), A377797 (volume).

Cf. A000796, A002163, A002194, A010476, A010476.

Sequence in context: A239121 A019875 A388836 * A388674 A388862 A388560

Adjacent sequences: A381692 A381693 A381694 * A381696 A381697 A381698

Keyword

nonn,cons,easy

Author

Paolo Xausa, Mar 08 2025

Status

approved