A386741 Decimal expansion of the volume of a hebesphenomegacorona with unit edges.

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

Offset

1,1

Comments

The hebesphenomegacorona is Johnson solid J_89.

Links

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

Wikipedia, Hebesphenomegacorona.

Formula

Equals the largest real root of 47330370277129322496*x^20 - 722445512980071186432*x^18 + 3596480447590271287296*x^16 - 8432333285523990773760*x^14 + 8973584611317745975296*x^12 - 3065290664181478981632*x^10 + 366229890219212144640*x^8 - 8337259437908852736*x^6 - 22211277300912896*x^4 + 132615435213216*x^2 + 2693461945329.

Example

2.912910414540209166042800910083320363836153037751...

Mathematica

First[RealDigits[Root[47330370277129322496*#^20 - 722445512980071186432*#^18 + 3596480447590271287296*#^16 - 8432333285523990773760*#^14 + 8973584611317745975296*#^12 - 3065290664181478981632*#^10 + 366229890219212144640*#^8 - 8337259437908852736*#^6 - 22211277300912896*#^4 + 132615435213216*#^2 + 2693461945329 &, 8], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["J89", "Volume"], 10, 100]]

Crossrefs

Cf. A386742 (surface area).

Cf. A386739, A386740.

Sequence in context: A199381 A083649 A073009 * A011064 A086773 A176124

Adjacent sequences: A386738 A386739 A386740 * A386742 A386743 A386744

Keyword

nonn,cons,easy

Author

Paolo Xausa, Aug 01 2025

Status

approved