A381672 Decimal expansion of the isoperimetric quotient of a regular icosahedron.

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

Offset: 0

Author

Paolo Xausa, Mar 03 2025

Keywords

• nonn
• cons
• easy

Comments

For the definition of isoperimetric quotient of a solid, see A381671.

Examples

			0.8287977192520120215005810038129635758617830308723...
		

Links

• Paolo Xausa, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A273637 (sphericity).

Cf. isoperimetric quotient of other Platonic solids: A019673 (cube), A073010 (octahedron), A374772 (dodecahedron), A381671 (tetrahedron).

Cf. A000796, A002194, A374883.

Programs

Mathematica

First[RealDigits[Pi*GoldenRatio^4/(15*Sqrt[3]), 10, 100]]

Formula

Equals Pi*phi^4/(15*sqrt(3)) = A000796*A374883/(15*A002194).