A394537 Decimal expansion of the circumradius of a uniform octagonal antiprism with unit edges.

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

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

David I. McCooey, Octagonal Antiprism.

Polytope Wiki, Octagonal antiprism.

Eric Weisstein's World of Mathematics, Antiprism.

Wikipedia, Antiprism.

Formula

Equals sqrt(4 + csc(Pi/16)^2)/4.

Equals the largest root of 512*x^8 - 1536*x^6 + 1280*x^4 - 416*x^2 + 47.

Example

1.3755485807735077126939276792065837776863256143470...

Mathematica

First[RealDigits[Sqrt[4 + Csc[Pi/16]^2]/4, 10, 100]] (* or *)
First[RealDigits[Min[PolyhedronData["OctagonalAntiprism", "Circumradius"]], 10, 100]]

Crossrefs

Cf. A394534 (volume), A394535 (surface area), A394536 (midradius), A394538 (height).

Cf. A387320, A387323 (dihedral angles).

Sequence in context: A397377 A205528 A021731 * A084726 A107738 A341628

Adjacent sequences: A394534 A394535 A394536 * A394538 A394539 A394540

Keyword

nonn,cons,easy

Author

Paolo Xausa, Apr 08 2026

Status

approved