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 A386001 #13 Jul 19 2025 10:11:25 %S A386001 7,3,2,6,4,9,5,7,1,1,2,2,7,9,9,7,3,8,5,1,8,6,3,4,3,8,5,9,0,4,8,1,6,9, %T A386001 2,5,6,9,0,0,6,2,9,0,7,7,2,9,3,5,7,0,7,7,2,6,9,1,0,4,2,8,4,5,3,8,6,5, %U A386001 2,3,2,4,7,7,6,2,8,9,8,7,4,0,3,4,8,7,5,6,4,5 %N A386001 Decimal expansion of the surface area of a tridiminished icosahedron with unit edge. %C A386001 The tridiminished icosahedron is Johnson solid J_63. %H A386001 Paolo Xausa, <a href="/A386001/b386001.txt">Table of n, a(n) for n = 1..10000</a> %H A386001 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tridiminished_icosahedron">Tridiminished icosahedron</a>. %F A386001 Equals (5*sqrt(3) + 3*sqrt(5*(5 + 2*sqrt(5))))/4 = (5*A002194 + 3*sqrt(5*(5 + A010476)))/4. %F A386001 Equals 3*A102771 + 5*A120011 = A386003 - 2*A120011. %F A386001 Equals the largest root of 256*x^8 - 19200*x^6 + 324000*x^4 - 1687500*x^2 + 1265625. %e A386001 7.32649571122799738518634385904816925690062907729... %t A386001 First[RealDigits[(5*Sqrt[3] + 3*Sqrt[25 + 10*Sqrt[5]])/4, 10, 100]] (* or *) %t A386001 First[RealDigits[PolyhedronData["J63", "SurfaceArea"], 10, 100]] %Y A386001 Cf. A386000 (volume). %Y A386001 Cf. A002194, A010476, A102771, A120011, A386003. %K A386001 nonn,cons,easy %O A386001 1,1 %A A386001 _Paolo Xausa_, Jul 17 2025