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 A387297 #11 Sep 02 2025 04:01:15 %S A387297 1,7,2,6,1,2,0,6,6,2,2,9,4,6,7,3,4,6,9,4,2,6,9,4,3,4,0,3,0,9,7,0,5,0, %T A387297 2,7,7,3,4,1,4,6,8,6,9,1,0,5,3,9,0,3,0,8,3,9,4,4,9,7,0,3,7,0,0,6,3,8, %U A387297 6,5,2,6,3,0,5,3,7,5,7,7,6,1,8,6,8,7,5,4,7,7 %N A387297 Decimal expansion of the smallest dihedral angle, in radians, in a gyroelongated triangular cupola (Johnson solid J_22). %C A387297 This is the dihedral angle between a triangular face and the hexagonal face. %H A387297 Paolo Xausa, <a href="/A387297/b387297.txt">Table of n, a(n) for n = 1..10000</a> %H A387297 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_triangular_cupola">Gyroelongated triangular cupola</a>. %F A387297 Equals arccos(1 - 2*sqrt(3)/3) = arccos(1 - A010469/3). %e A387297 1.7261206622946734694269434030970502773414686910539... %t A387297 First[RealDigits[ArcCos[1 - 2/Sqrt[3]], 10, 100]] (* or *) %t A387297 First[RealDigits[Min[PolyhedronData["J22", "DihedralAngles"]], 10, 100]] %Y A387297 Cf. other J_22 dihedral angles: A195698, A387294, A387295, A387296. %Y A387297 Cf. A344076 (J_22 volume), A344077 (J_22 surface area). %Y A387297 Cf. A010469. %K A387297 nonn,cons,easy,new %O A387297 1,2 %A A387297 _Paolo Xausa_, Aug 26 2025