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 A387296 #11 Sep 02 2025 05:57:46 %S A387296 2,5,3,4,6,0,0,1,4,9,7,1,5,1,2,6,1,9,3,0,9,1,5,0,2,8,1,0,2,1,0,2,1,0, %T A387296 7,0,2,1,4,9,8,3,0,3,2,9,1,9,3,5,1,5,3,6,3,6,8,8,4,3,4,6,4,6,4,1,3,6, %U A387296 2,5,9,5,0,3,8,5,3,4,7,9,8,9,3,8,8,4,6,2,6,1 %N A387296 Decimal expansion of the third largest dihedral angle, in radians, in a gyroelongated triangular cupola (Johnson solid J_22). %C A387296 This is the dihedral angle between triangular faces in the antiprism part of the solid. %C A387296 Also the analogous dihedral angle in a gyroelongated triangular bicupola (Johnson solid J_44). %H A387296 Paolo Xausa, <a href="/A387296/b387296.txt">Table of n, a(n) for n = 1..10000</a> %H A387296 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_triangular_bicupola">Gyroelongated triangular bicupola</a>. %H A387296 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_triangular_cupola">Gyroelongated triangular cupola</a>. %F A387296 Equals arccos((1 - 2*sqrt(3))/3) = arccos((1 - A010469)/3). %e A387296 2.5346001497151261930915028102102107021498303291935... %t A387296 First[RealDigits[ArcCos[(1 - Sqrt[12])/3], 10, 100]] (* or *) %t A387296 First[RealDigits[RankedMax[Union[PolyhedronData["J22", "DihedralAngles"]], 3], 10, 100]] %Y A387296 Cf. other J_22 dihedral angles: A195698, A387294, A387295, A387297. %Y A387296 Cf. A344076 (J_22 volume), A344077 (J_22 surface area). %Y A387296 Cf. A385256 (J_44 volume), A385257 (J_44 surface area). %Y A387296 Cf. A010469. %K A387296 nonn,cons,easy,new %O A387296 1,1 %A A387296 _Paolo Xausa_, Aug 26 2025