A385578 Decimal expansion of the volume of a parabiaugmented hexagonal prism with unit edge.

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

Offset: 1

Author

Paolo Xausa, Jul 04 2025

Keywords

• nonn
• cons
• easy

Comments

The parabiaugmented hexagonal prism is Johnson solid J_55.

Also the volume of a metabiaugmented hexagonal prism (Johnson solid J_56) with unit edge.

Examples

			3.0694807321443476232250657536620412432707651725...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000
• Wikipedia, Parabiaugmented hexagonal prism.

Crossrefs

Cf. A385257 (surface area + 2).

Cf. A002194, A010466, A104956, A131594, A385569.

Programs

Mathematica

First[RealDigits[(Sqrt[8] + 9*Sqrt[3])/6, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["J55", "Volume"], 10, 100]]

Formula

Equals (2*sqrt(2) + 9*sqrt(3))/6 = (A010466 + 9*A002194)/6 = A131594 + A104956.

Equals the largest root of 1296*x^4 - 18072*x^2 + 55225.