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 A386545 #10 Jul 28 2025 10:53:44 %S A386545 1,0,4,5,6,4,7,5,6,3,5,4,4,3,7,7,7,8,6,4,4,4,7,3,7,2,9,3,8,1,1,7,2,6, %T A386545 8,3,0,4,9,1,2,2,4,6,6,7,1,0,4,7,1,7,5,5,0,9,1,4,9,0,6,1,0,8,2,4,7,1, %U A386545 0,4,4,4,8,6,5,7,1,8,4,4,4,6,8,3,6,8,5,7,1,1 %N A386545 Decimal expansion of the surface area of a triaugmented truncated dodecahedron with unit edges. %C A386545 The triaugmented truncated dodecahedron is Johnson solid J_71. %H A386545 Paolo Xausa, <a href="/A386545/b386545.txt">Table of n, a(n) for n = 3..10000</a> %H A386545 Wikipedia, <a href="https://en.wikipedia.org/wiki/Triaugmented_truncated_dodecahedron">Triaugmented truncated dodecahedron</a>. %F A386545 Equals (60 + 35*sqrt(3) + 90*sqrt(5 + 2*sqrt(5)) + 3*sqrt(5*(5 + 2*sqrt(5))))/4 = (60 + 35*A002194 + 90*sqrt(5 + A010476) + 3*sqrt(5*(5 + A010476)))/4. %F A386545 Equals the largest root of 256*x^8 - 30720*x^7 - 1574400*x^6 + 238464000*x^5 + 68364000*x^4 - 390828240000*x^3 + 4437895162500*x^2 + 78660973125000*x - 1021409416546875. %e A386545 104.56475635443777864447372938117268304912246671047... %t A386545 First[RealDigits[(60 + 35*Sqrt[3] + 90*Sqrt[#] + 3*Sqrt[5*#])/4 & [5 + Sqrt[20]], 10, 100]] (* or *) %t A386545 First[RealDigits[PolyhedronData["J71", "SurfaceArea"], 10, 100]] %Y A386545 Cf. A386544 (volume). %Y A386545 Cf. A002194, A010476, A377694, A385805, A386465, A386543. %K A386545 nonn,cons,easy %O A386545 3,3 %A A386545 _Paolo Xausa_, Jul 28 2025