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 A378354 #7 Nov 28 2024 11:11:19 %S A378354 2,5,7,1,7,4,4,4,0,0,3,4,5,6,6,8,4,6,7,9,1,2,8,5,4,0,5,0,9,2,8,0,6,3, %T A378354 7,9,3,5,5,1,1,5,6,9,4,1,1,1,3,8,5,9,7,4,5,3,2,5,4,4,5,4,2,6,8,0,3,6, %U A378354 3,5,1,6,5,6,1,5,2,6,3,5,8,7,9,1,4,6,0,6,6,5 %N A378354 Decimal expansion of the dihedral angle, in radians, between any two adjacent faces in a (small) triakis octahedron. %C A378354 The (small) triakis octahedron is the dual polyhedron of the truncated cube. %H A378354 Wikipedia, <a href="https://en.wikipedia.org/wiki/Triakis_octahedron">Triakis octahedron</a>. %F A378354 Equals arccos(-(3 + 8*sqrt(2))/17) = arccos(-(3 + A377342)/17). %e A378354 2.57174440034566846791285405092806379355115694111... %t A378354 First[RealDigits[ArcCos[-(3 + 8*Sqrt[2])/17], 10, 100]] (* or *) %t A378354 First[RealDigits[First[PolyhedronData["TriakisOctahedron", "DihedralAngles"]], 10, 100]] %Y A378354 Cf. A378351 (surface area), A378352 (volume), A378353 (inradius), A201488 (midradius). %Y A378354 Cf. A019669 and A195698 (dihedral angles of a truncated cube). %Y A378354 Cf. A377342. %K A378354 nonn,cons,easy %O A378354 1,1 %A A378354 _Paolo Xausa_, Nov 24 2024