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 A387322 #12 Sep 02 2025 04:01:27 %S A387322 2,4,7,1,2,9,0,5,4,5,6,4,6,9,7,8,5,7,5,4,7,3,2,5,4,7,9,6,1,5,5,2,5,3, %T A387322 7,9,9,4,8,5,7,4,9,3,3,3,0,8,8,6,0,0,4,9,0,5,5,9,0,9,1,7,6,3,3,7,9,5, %U A387322 6,7,4,2,7,0,4,6,5,3,8,4,9,4,3,2,1,6,9,2,5,4 %N A387322 Decimal expansion of the fourth largest dihedral angle, in radians, in a gyroelongated square cupola (Johnson solid J_23). %C A387322 This is the dihedral angle between a triangular face and a square face at the edge where the antiprism and cupola parts of the solid meet. %C A387322 Also the analogous dihedral angle in a gyroelongated square bicupola (Johnson solid J_45). %H A387322 Paolo Xausa, <a href="/A387322/b387322.txt">Table of n, a(n) for n = 1..10000</a> %H A387322 Polytope Wiki, <a href="https://polytope.miraheze.org/wiki/Gyroelongated_square_bicupola">Gyroelongated square bicupola</a>. %H A387322 Polytope Wiki, <a href="https://polytope.miraheze.org/wiki/Gyroelongated_square_cupola">Gyroelongated square cupola</a>. %H A387322 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_square_bicupola">Gyroelongated square bicupola</a>. %H A387322 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_square_cupola">Gyroelongated square cupola</a>. %F A387322 Equals Pi/4 + arccos(-sqrt((7 + 4*sqrt(2) - 2*sqrt(20 + 14*sqrt(2)))/3)) = A003881 + arccos(-sqrt((7 + A010487 - 2*sqrt(20 + 14*A002193))/3)). %F A387322 Equals A003881 + A387323. %e A387322 2.4712905456469785754732547961552537994857493330886... %t A387322 First[RealDigits[Pi/4 + ArcCos[-Sqrt[(7 + Sqrt[32] - 2*Sqrt[20 + 14*Sqrt[2]])/3]], 10, 100]] (* or *) %t A387322 First[RealDigits[RankedMax[Union[PolyhedronData["J23", "DihedralAngles"]], 4], 10, 100]] %Y A387322 Cf. other J_23 dihedral angles: A177870, A195702, A387320, A387321, A387323. %Y A387322 Cf. A384214 (J_23 volume), A384215 (J_23 surface area). %Y A387322 Cf. A385258 (J_45 volume), A385259 (J_45 surface area). %Y A387322 Cf. A003881, A002193, A010487. %K A387322 nonn,cons,easy,new %O A387322 1,1 %A A387322 _Paolo Xausa_, Aug 29 2025