A377804 Decimal expansion of the surface area of a snub dodecahedron with unit edge length.

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

Offset

2,1

Links

Table of n, a(n) for n=2..91.

Eric Weisstein's World of Mathematics, Snub Dodecahedron.

Wikipedia, Snub dodecahedron.

Index entries for algebraic numbers, degree 8.

Formula

Equals 20*sqrt(3) + 3*sqrt(25 + 10*sqrt(5)) = 20*A002194 + A131595.

Example

55.2867449584451489436570705587807625317445951163...

Mathematica

First[RealDigits[20*Sqrt[3] + 3*Sqrt[25 + 10*Sqrt[5]], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["SnubDodecahedron", "SurfaceArea"], 10, 100]]

Crossrefs

Cf. A377805 (volume), A377806 (circumradius), A377807 (midradius).

Cf. A131595 (analogous for a regular dodecahedron).

Cf. A002194.

Sequence in context: A023580 A021648 A287746 * A377751 A128006 A157703

Adjacent sequences: A377801 A377802 A377803 * A377805 A377806 A377807

Keyword

nonn,cons,easy

Author

Paolo Xausa, Nov 08 2024

Status

approved