cp's OEIS Frontend

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.

A377995 Decimal expansion of the dihedral angle, in radians, between square and pentagonal faces in a (small) rhombicosidodecahedron.

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%I A377995 #9 Nov 16 2024 07:25:47
%S A377995 2,5,8,8,0,1,8,2,9,4,6,9,2,7,4,7,9,8,6,9,5,4,1,1,0,6,5,3,1,9,0,2,3,4,
%T A377995 3,6,4,1,6,2,1,4,5,5,7,6,6,7,4,3,8,9,4,9,7,6,3,6,6,7,4,9,8,8,5,9,0,9,
%U A377995 6,1,2,3,6,7,9,7,5,2,7,6,0,1,6,2,1,3,2,6,2,6
%N A377995 Decimal expansion of the dihedral angle, in radians, between square and pentagonal faces in a (small) rhombicosidodecahedron.
%C A377995 Also the dihedral angle, in radians, between square and 10-gonal faces in a truncated icosidodecahedron (great rhombicosidodecahedron).
%H A377995 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GreatRhombicosidodecahedron.html">Great Rhombicosidodecahedron</a>.
%H A377995 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SmallRhombicosidodecahedron.html">Small Rhombicosidodecahedron</a>.
%F A377995 Equals arccos(-sqrt((5 + sqrt(5))/10)) = arccos(-sqrt(A242671)).
%e A377995 2.588018294692747986954110653190234364162145576674...
%t A377995 First[RealDigits[ArcCos[-Sqrt[(5 + Sqrt[5])/10]], 10, 100]] (* or *)
%t A377995 First[RealDigits[Min[PolyhedronData["Rhombicosidodecahedron", "DihedralAngles"]], 10, 100]]
%Y A377995 Cf. A242671, A377996.
%K A377995 nonn,cons,easy
%O A377995 1,1
%A A377995 _Paolo Xausa_, Nov 15 2024