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 A386694 #7 Jul 31 2025 08:43:32 %S A386694 5,5,7,3,1,9,8,6,6,4,3,5,7,6,1,9,9,4,4,1,0,1,7,5,9,5,0,4,3,6,5,6,6,5, %T A386694 0,5,3,3,3,9,5,1,4,0,1,7,3,8,8,8,2,0,3,9,5,0,7,2,7,2,8,2,9,6,5,3,4,1, %U A386694 2,1,1,8,6,4,7,2,9,8,7,8,0,1,6,7,5,2,8,5,6,8 %N A386694 Decimal expansion of the surface area of a tridiminished rhombicosidodecahedron with unit edges. %C A386694 The tridiminished rhombicosidodecahedron is Johnson solid J_83. %H A386694 Paolo Xausa, <a href="/A386694/b386694.txt">Table of n, a(n) for n = 2..10000</a> %H A386694 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tridiminished_rhombicosidodecahedron">Tridiminished rhombicosidodecahedron</a>. %F A386694 Equals (60 + 5*sqrt(3) + 30*sqrt(5 + 2*sqrt(5)) + 9*sqrt(5*(5 + 2*sqrt(5))))/4 = (60 + 5*A002194 + 30*sqrt(5 + A010476) + 9*sqrt(5*(5 + A010476)))/4. %F A386694 Equals the largest root of 256*x^8 - 30720*x^7 + 844800*x^6 + 20736000*x^5 - 1109916000*x^4 + 6460560000*x^3 + 265641862500*x^2 - 4344667875000*x + 19010422828125. %e A386694 55.731986643576199441017595043656650533395140173888... %t A386694 First[RealDigits[(60 + 5*Sqrt[3] + 30*Sqrt[#] + 9*Sqrt[5*#])/4 & [5 + Sqrt[20]], 10, 100]] (* or *) %t A386694 First[RealDigits[PolyhedronData["J83", "SurfaceArea"], 10, 100]] %Y A386694 Cf. A386693 (volume). %Y A386694 Cf. A002194, A010476, A344149, A386690, A386692. %K A386694 nonn,cons,easy %O A386694 2,1 %A A386694 _Paolo Xausa_, Jul 31 2025