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A236556
Decimal expansion of the steradian solid angle subtended by one square facet of the cuboctahedron.
6
1, 3, 5, 9, 3, 4, 7, 6, 3, 7, 8, 1, 6, 4, 8, 7, 7, 4, 8, 3, 8, 5, 5, 7, 0, 0, 5, 3, 5, 6, 7, 0, 5, 6, 2, 6, 5, 5, 5, 2, 9, 7, 8, 7, 6, 1, 3, 2, 9, 8, 3, 2, 2, 8, 5, 7, 2, 7, 6, 9, 5, 8, 4, 9, 9, 5, 9, 6, 6, 3, 5, 5, 4, 6, 5, 9, 3, 9, 3, 6, 4, 5, 8, 4, 3, 0, 6, 3, 1, 7, 0, 0, 0, 0, 7, 9, 0, 4, 5, 1, 4, 0, 8, 5, 1
OFFSET
1,2
COMMENTS
Also the vertex solid angle of a regular octahedron.
LINKS
Eric Weisstein's World of Mathematics, Cuboctahedron.
Eric Weisstein's World of Mathematics, Spherical Polygon.
Wikipedia, Platonic solid.
FORMULA
Equals 4*arcsin(1/3) = 4*A188615.
Equals 2*Pi - 4*arcsin(2*sqrt(2)/3). - Bradley Klee, Oct 04 2018
8*A236555 + 6*this = 4*Pi. - Bradley Klee, Oct 04 2018
EXAMPLE
1.35934763781648774838557005356705626555297876132983228572769584995966...
MAPLE
evalf(4*arcsin(1/3), 100) ; # R. J. Mathar, Apr 26 2021
MATHEMATICA
RealDigits[4*ArcSin[1/3], 10, 120][[1]] (* Amiram Eldar, May 22 2023 *)
PROG
(PARI) 4*asin(1/3)
CROSSREFS
Cf. A188615, A236555. Icosidodecahedron: A319881, A319883. Vertex Angles: A019669, A236557, A236558.
Sequence in context: A303772 A200510 A138055 * A189044 A299793 A356527
KEYWORD
nonn,cons,easy
AUTHOR
Stanislav Sykora, Jan 28 2014
EXTENSIONS
Definition corrected by Bradley Klee, Oct 04 2018
STATUS
approved