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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.

A377997 Decimal expansion of the dihedral angle, in radians, between triangular faces in a snub dodecahedron.

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%I A377997 #6 Nov 16 2024 07:25:44
%S A377997 2,8,6,5,4,0,0,6,8,8,3,4,4,7,2,8,6,0,7,6,0,4,6,0,7,3,4,1,7,3,3,6,5,6,
%T A377997 9,1,4,1,1,9,0,0,9,6,7,2,6,6,5,2,3,7,9,6,9,0,5,9,9,2,8,5,2,5,2,2,0,3,
%U A377997 5,8,6,9,8,3,4,3,4,2,9,0,1,8,5,7,2,8,8,7,8,0
%N A377997 Decimal expansion of the dihedral angle, in radians, between triangular faces in a snub dodecahedron.
%H A377997 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SnubDodecahedron.html">Snub Dodecahedron</a>.
%H A377997 Wikipedia, <a href="https://en.wikipedia.org/wiki/Snub_dodecahedron">Snub dodecahedron</a>.
%F A377997 Equals Pi - arccos((2/3)*A377849 + 1/3).
%F A377997 Equals Pi - arccos(c), where c is the largest real root of 729*x^6 + 486*x^5 - 729*x^4 - 756*x^3 + 63*x^2 + 270*x + 1.
%e A377997 2.8654006883447286076046073417336569141190096726652...
%t A377997 First[RealDigits[Pi - ArcCos[2*Root[#^3 + 2*#^2 - GoldenRatio^2 &, 1]/3 + 1/3], 10, 100]] (* or *)
%t A377997 First[RealDigits[Max[PolyhedronData["SnubDodecahedron", "DihedralAngles"]], 10, 100]]
%Y A377997 Cf. A377804, A377805, A377806, A377807, A377849, A377998.
%K A377997 nonn,cons,easy
%O A377997 1,1
%A A377997 _Paolo Xausa_, Nov 15 2024