

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.


16



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
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OFFSET

1,2


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


LINKS

Eric Weisstein's World of Mathematics, Pentagon


FORMULA

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


EXAMPLE

1.53884176858762670128514528801845491200335107176889621351957812518743...


MAPLE

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


MATHEMATICA

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


PROG

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


CROSSREFS



KEYWORD



AUTHOR



EXTENSIONS



STATUS

approved



