A377697 Decimal expansion of the midradius of a truncated dodecahedron with unit edge length.

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

Offset: 1

Author

Paolo Xausa, Nov 05 2024

Keywords

• nonn
• cons
• easy

Examples

			2.9270509831248422723068802515484571765804637697...
		

Links

• Eric Weisstein's World of Mathematics, Truncated Dodecahedron.
• Wikipedia, Truncated dodecahedron.

Crossrefs

Cf. A377694 (surface area), A377695 (volume), A377696 (circumradius), A377698 (Dehn invariant, negated).

Cf. A239798 (analogous for a regular dodecahedron).

Cf. A010499, A205769.

Programs

Mathematica

First[RealDigits[(5 + Sqrt[45])/4, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["TruncatedDodecahedron", "Midradius"], 10, 100]]

Formula

Equals (5 + 3*sqrt(5))/4 = (5 + A010499)/4.

Equals A205769 - 1/2.