A385257 Decimal expansion of the surface area of a gyroelongated triangular bicupola with unit edge.

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

Offset: 2

Author

Paolo Xausa, Jun 24 2025

Keywords

• nonn
• cons
• easy

Comments

The gyroelongated triangular bicupola is Johnson solid J_44.

Examples

			14.660254037844386467637231707529361834714026269...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 2..10000
• Wikipedia, Gyroelongated triangular bicupola.

Crossrefs

Cf. A385256 (volume).

Cf. A002194, A010527.

Essentially the same of A332133, A375193 and A010527.

Programs

Mathematica

First[RealDigits[6 + 5*Sqrt[3], 10, 100]] (* or *)
First[RealDigits[PolyhedronData["J44", "SurfaceArea"], 10, 100]]

Formula

Equals 6 + 5*sqrt(3) = 6 + 5*A002194 = 6 + 10*A010527.

Equals the largest root of x^2 - 12*x - 39.