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

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

1,1

Comments

The triaugmented dodecahedron is Johnson solid J_61.

Links

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

Wikipedia, Triaugmented dodecahedron.

Formula

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

Example

8.56762745781210568076720062887114294145115942427...

Mathematica

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

Crossrefs

Cf. A385805 (surface area).

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

Sequence in context: A154013 A230152 A099002 * A365281 A021898 A020786

Adjacent sequences: A385801 A385802 A385803 * A385805 A385806 A385807

Keyword

nonn,cons,easy

Author

Paolo Xausa, Jul 09 2025

Status

approved