A179637 Decimal expansion of the surface area of pentagonal rotunda with edge length 1.

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

Offset

2,1

Comments

Pentagonal rotunda: 20 vertices, 35 edges, and 17 faces.

Links

Table of n, a(n) for n=2..106.

Wolfram Alpha, Johnson solid 6

Formula

Digits of sqrt(5*(145+58*sqrt(5)+2*sqrt(30*(65+29*sqrt(5)))))/2.

Example

22.3472002653941282767984141581886130738180135134316226129799763167102...

Mathematica

RealDigits[N[Sqrt[5*(145+58*Sqrt[5]+2*Sqrt[30*(65+29*Sqrt[5])])]/2, 200]]

Crossrefs

Cf. A001622, A010527, A102208, A179290, A179292, A179294, A179449-A179452, A179552-A179554, A179587-A179593.

Sequence in context: A065482 A323481 A319638 * A054241 A277320 A343399

Adjacent sequences: A179634 A179635 A179636 * A179638 A179639 A179640

Keyword

cons,nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, Jul 21 2010

Extensions

Offset corrected by R. J. Mathar, Aug 15 2010

Status

approved