This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A319881 #26 Feb 16 2025 08:33:56 %S A319881 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, %T A319881 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, %U A319881 4,6,1,0,6,4,5,8,7,9,3,8 %N A319881 Decimal expansion of the steradian solid angle subtended by one triangular facet of the icosidodecahedron. %H A319881 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Icosidodecahedron.html">Icosidodecahedron</a> %H A319881 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SphericalPolygon.html">Spherical Polygon</a> %F A319881 Equals 3*arctan(2) - Pi. %F A319881 Equals (Pi - 3*A319883)/5. %e A319881 0.17985349979247827058855299725610823601297353682919... %t A319881 RealDigits[3*ArcTan[2] - Pi, 10, 80][[1]] %o A319881 (PARI) 3*atan(2)-Pi \\ _Altug Alkan_, Oct 03 2018 %Y A319881 Cf. A319883. Cuboctahedron: A236555, A236556. %K A319881 nonn,cons %O A319881 0,2 %A A319881 _Bradley Klee_, Sep 30 2018