A179452 Decimal expansion of sqrt(5 + 2*sqrt(5))/2, the height of a regular pentagon and midradius of an icosidodecahedron with side length 1.

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

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jul 14 2010

Keywords

• nonn
• cons
• easy

Comments

Icosidodecahedron: 32 faces, 30 vertices, and 60 edges.

Height of a regular pentagon with side length 1. - Jared Kish, Oct 16 2014

Volume of a regular decagonal prism with unit side length and height 2. - Wesley Ivan Hurt, May 04 2021

Examples

			1.53884176858762670128514528801845491200335107176889621351957812518743...
		

Links

• Eric Weisstein's World of Mathematics, Icosidodecahedron
• Eric Weisstein's World of Mathematics, Pentagon
• Index entries for algebraic numbers, degree 4

Crossrefs

Cf. A010527, A102208, A179290, A179292, A179294, A179449, A179450, A179451.

Programs

Maple

sqrt(5+2*sqrt(5.))/2

Mathematica

RealDigits[Sqrt[5+2Sqrt[5]]/2,10,120][[1]] (* Harvey P. Dale, Jun 23 2017 *)

PARI

sqrt(5+2*sqrt(5))/2

Formula

Equals sqrt(5+2*sqrt(5))/2.

Extensions

Partially rewritten by Charles R Greathouse IV, Feb 03 2011

Edited by M. F. Hasler, Oct 16 2014