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 A236558 #14 May 22 2023 02:45:40 %S A236558 2,9,6,1,7,3,9,1,5,3,7,9,7,3,1,4,9,6,7,8,7,4,0,9,0,3,8,6,0,2,3,3,9,4, %T A236558 6,4,8,1,8,4,1,9,5,8,6,2,5,4,5,9,1,3,7,0,1,9,2,0,2,7,1,5,6,2,3,1,4,5, %U A236558 0,1,7,9,5,6,4,0,3,2,9,6,1,5,2,1,5,8,1,8,2,6,4,6,2,5,7,2,2,2,1,1,6,6,0,6,6 %N A236558 Vertex solid angle (steradians) in a regular dodecahedron. %H A236558 Stanislav Sykora, <a href="/A236558/b236558.txt">Table of n, a(n) for n = 1..2000</a> %H A236558 Wikipedia, <a href="http://en.wikipedia.org/wiki/Platonic_solid">Platonic solid</a>. %F A236558 Equals Pi - arctan(2/11). %e A236558 2.9617391537973149678740903860233946481841958625459137019202715623145... %t A236558 RealDigits[Pi - ArcTan[2/11], 10, 120][[1]] (* _Amiram Eldar_, May 22 2023 *) %o A236558 (PARI) Pi-atan(2/11) %Y A236558 Cf. Analogs: A236555 (tetrahedron), A236556 (octahedron), A019669 (cube), A236557 (icosahedron). %K A236558 nonn,cons,easy %O A236558 1,1 %A A236558 _Stanislav Sykora_, Jan 28 2014