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 A379389 #6 Dec 24 2024 08:43:57 %S A379389 2,6,8,9,9,2,5,2,3,4,2,0,6,5,7,6,3,4,0,0,7,2,8,8,1,5,1,4,6,3,1,6,1,6, %T A379389 8,3,0,0,3,5,3,3,0,3,7,2,4,9,2,1,1,4,1,4,3,1,6,0,1,1,4,5,0,7,8,1,7,2, %U A379389 8,3,1,9,1,3,5,1,4,1,4,4,0,1,8,9,8,9,6,6,3,8 %N A379389 Decimal expansion of the dihedral angle, in radians, between any two adjacent faces in a deltoidal hexecontahedron. %C A379389 The deltoidal hexecontahedron is the dual polyhedron of the (small) rhombicosidodecahedron. %H A379389 Paolo Xausa, <a href="/A379389/b379389.txt">Table of n, a(n) for n = 1..10000</a> %H A379389 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DeltoidalHexecontahedron.html">Deltoidal Hexecontahedron</a>. %H A379389 Wikipedia, <a href="https://en.wikipedia.org/wiki/Deltoidal_hexecontahedron">Deltoidal hexecontahedron</a>. %F A379389 Equals arccos(-(19 + 8*sqrt(5))/41) = arccos(-(19 + 8*A002163)/41). %e A379389 2.6899252342065763400728815146316168300353303724921... %t A379389 First[RealDigits[ArcCos[-(19 + 8*Sqrt[5])/41], 10, 100]] (* or *) %t A379389 First[RealDigits[First[PolyhedronData["DeltoidalHexecontahedron", "DihedralAngles"]], 10, 100]] %Y A379389 Cf. A379385 (surface area), A379386 (volume), A379387 (inradius), A379388 (midradius). %Y A379389 Cf. A377995 and A377996 (dihedral angles of a (small) rhombicosidodecahedron). %Y A379389 Cf. A002163. %K A379389 nonn,cons,easy %O A379389 1,1 %A A379389 _Paolo Xausa_, Dec 23 2024