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A236555
Decimal expansion of the steradian solid angle subtended by one triangular facet of the cuboctahedron.
7
5, 5, 1, 2, 8, 5, 5, 9, 8, 4, 3, 2, 5, 3, 0, 8, 0, 7, 9, 4, 2, 1, 4, 4, 1, 5, 1, 4, 6, 4, 4, 5, 9, 2, 4, 2, 9, 3, 3, 8, 5, 0, 6, 2, 8, 6, 9, 0, 1, 7, 8, 6, 9, 6, 1, 9, 1, 7, 0, 0, 4, 0, 8, 6, 8, 4, 1, 6, 0, 5, 3, 7, 1, 4, 8, 5, 5, 9, 2, 6, 4, 9, 3, 1, 7, 2, 0, 0, 3, 5, 1, 7, 0, 4, 6, 5, 6, 9, 5, 4, 3, 4, 6, 8, 4, 7, 5
OFFSET
0,1
COMMENTS
Also the vertex solid angle of a regular tetrahedron.
LINKS
Eric Weisstein's World of Mathematics, Cuboctahedron
Eric Weisstein's World of Mathematics, Spherical Polygon
Wikipedia, Platonic solid
FORMULA
arccos(23/27).
3*arcsin(2*sqrt(2)/3) - Pi. - Bradley Klee, Oct 04 2018
8*A236555 + 6*A236556 = 4*Pi. - Bradley Klee, Oct 04 2018
EXAMPLE
0.55128559843253080794214415146445924293385062869017869619170040868416...
MATHEMATICA
RealDigits[N[ArcCos[23/27], 107]][[1]] (* T. D. Noe, Jan 29 2014 *)
CROSSREFS
Cf. A236556. Icosidodecahedron: A319881, A319883. Vertex Angles: A019669, A236557, A236558.
Sequence in context: A156696 A232651 A145227 * A282969 A046095 A322545
KEYWORD
nonn,cons,easy
AUTHOR
Stanislav Sykora, Jan 28 2014
EXTENSIONS
Definition corrected by Bradley Klee, Oct 04 2018
STATUS
approved