A377799 Decimal expansion of the midradius of a truncated icosidodecahedron (great rhombicosidodecahedron) with unit edge length.

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

Offset

1,1

Links

Table of n, a(n) for n=1..90.

Polytope Wiki, Great rhombicosidodecahedron.

Eric Weisstein's World of Mathematics, Great Rhombicosidodecahedron.

Wikipedia, Truncated icosidodecahedron.

Index entries for algebraic numbers, degree 4.

Formula

Equals sqrt(15/2 + 3*sqrt(5)) = sqrt(15/2 + A010499) = sqrt(30 + A344171)/2.

Minimal polynomial: 4*x^4 - 60*x^2 + 45. - Amiram Eldar, Jun 09 2026

Example

3.76937712792171660267226420066194243563005157196...

Mathematica

First[RealDigits[Sqrt[15/2 + Sqrt[45]], 10, 100]]
(* Alternative: *)
First[RealDigits[PolyhedronData["TruncatedIcosidodecahedron", "Midradius"], 10, 100]]

Crossrefs

Cf. A377796 (surface area), A377797 (volume), A377798 (circumradius).

Cf. A010499, A344171.

Sequence in context: A347155 A371240 A117823 * A338067 A178242 A352168

Adjacent sequences: A377796 A377797 A377798 * A377800 A377801 A377802

Keyword

nonn,cons,easy,changed

Author

Paolo Xausa, Nov 08 2024

Status

approved