A377605 Decimal expansion of the midradius of a snub cube (snub cuboctahedron) with unit edge length.

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

Offset: 1

Author

Paolo Xausa, Nov 03 2024

Keywords

• nonn
• cons
• easy

Examples

			1.2472231679936432517699189608980305834168701800...
		

Links

• Eric Weisstein's World of Mathematics, Snub Cube.
• Wikipedia, Snub cube.
• Index entries for algebraic numbers, degree 6.

Crossrefs

Cf. A377602 (surface area), A377603 (volume), A377604 (circumradius).

Cf. A058265.

Programs

Mathematica

First[RealDigits[Sqrt[1/(8 - 4*#)], 10, 100]] & [Root[#^3 - #^2 - # - 1 &, 1]] (* or *)
First[RealDigits[PolyhedronData["SnubCube", "Midradius"], 10, 100]]

PARI

polrootsreal(64*x^6 - 112*x^4 + 20*x^2 - 1)[2] \\ Charles R Greathouse IV, Feb 11 2025

Formula

Equals sqrt(1/(4*(2 - A058265))).