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A319881 Decimal expansion of the steradian solid angle subtended by one triangular facet of the icosidodecahedron. 4
1, 7, 9, 8, 5, 3, 4, 9, 9, 7, 9, 2, 4, 7, 8, 2, 7, 0, 5, 8, 8, 5, 5, 2, 9, 9, 7, 2, 5, 6, 1, 0, 8, 2, 3, 6, 0, 1, 2, 9, 7, 3, 5, 3, 6, 8, 2, 9, 1, 9, 2, 1, 1, 9, 0, 5, 4, 6, 7, 3, 0, 2, 9, 9, 9, 3, 3, 1, 4, 6, 1, 0, 6, 4, 5, 8, 7, 9, 3, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..79.

Eric Weisstein's World of Mathematics, Icosidodecahedron

Eric Weisstein's World of Mathematics,  Spherical Polygon

FORMULA

3*arctan(2) - Pi.

20*A319881 + 12*A319883 = 4*Pi.

EXAMPLE

0.17985349979247827058855299725610823601297353682919...

MATHEMATICA

RealDigits[3*ArcTan[2] - Pi, 10, 80][[1]]

PROG

(PARI) 3*atan(2)-Pi \\ Altug Alkan, Oct 03 2018

CROSSREFS

Cf. A319883. Cuboctahedron: A236555, A236556.

Sequence in context: A228049 A154943 A126041 * A021560 A197516 A019862

Adjacent sequences:  A319878 A319879 A319880 * A319882 A319883 A319884

KEYWORD

nonn,cons

AUTHOR

Bradley Klee, Sep 30 2018

STATUS

approved

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Last modified July 9 03:41 EDT 2020. Contains 335538 sequences. (Running on oeis4.)