A394073 Decimal expansion of the midradius of a uniform heptagonal antiprism with unit edges.

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

Offset

1,3

Links

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

David I. McCooey, Heptagonal Antiprism.

Polytope Wiki, Heptagonal antiprism.

Eric Weisstein's World of Mathematics, Antiprism.

Wikipedia, Antiprism.

Index entries for algebraic numbers, degree 3.

Formula

Equals csc(Pi/14)/4 = 1/(4*sin(Pi/14)) = 1/(4*A232736).

Equals the largest root of 8*x^3 - 8*x^2 - 2*x + 1.

Equals 1/2 + A362922.

Example

1.1234898018587335305250048840042398106322747308964...

Mathematica

First[RealDigits[Csc[Pi/14]/4, 10, 100]] (* or *)
First[RealDigits[PolyhedronData["HeptagonalAntiprism", "Midradius"], 10, 100]]

Crossrefs

Cf. A394071 (volume), A394072 (surface area), A394074 (circumradius), A394075 (height).

Cf. A394076, A394077 (dihedral angles).

Cf. A232736.

Sequence in context: A019949 A172002 A274927 * A066338 A370662 A047453

Adjacent sequences: A394069 A394071 A394072 * A394074 A394075 A394076

Keyword

nonn,cons,easy

Author

Paolo Xausa, Mar 10 2026

Status

approved