

A179292


Decimal expansion of radius of inscribed sphere of an icosahedron with radius of circumscribed sphere = 1.


23



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

0,1


COMMENTS

Icosahedron: A three dimensional figure with 20 equilateral triangle faces, 12 vertices, and 30 edges.


LINKS

Table of n, a(n) for n=0..104.
Mathforum, Icosahedron
Wikipedia, Icosahedron
MathWorld, Icosahedron


FORMULA

Sqrt(75 + 30*sqrt(5))/15


EXAMPLE

0.794654472291766122955530928327594042026590588309264801754955775008438...


MATHEMATICA

R=1; RealDigits[N[(Sqrt[75+30*Sqrt[5]]/15)*R, 175]]


CROSSREFS

Cf. A010527, A102208, A179290.
Sequence in context: A102375 A216754 A118270 * A198756 A140899 A201925
Adjacent sequences: A179289 A179290 A179291 * A179293 A179294 A179295


KEYWORD

nonn,cons,easy


AUTHOR

Vladimir Joseph Stephan Orlovsky, Jul 09 2010


EXTENSIONS

Offset corrected, keyword:cons added by R. J. Mathar, Jul 11 2010


STATUS

approved



