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 A378973 #13 Mar 31 2025 03:29:17 %S A378973 2,6,2,2,8,5,9,5,9,7,6,7,4,3,7,5,1,6,8,1,4,5,8,1,9,5,1,0,4,3,5,6,8,0, %T A378973 1,7,3,1,8,6,5,2,6,6,6,9,9,5,1,9,3,4,2,6,0,1,6,3,9,6,2,5,7,1,7,6,8,9, %U A378973 9,0,4,3,5,9,5,8,6,7,6,7,7,0,9,4,7,3,8,5,1,9 %N A378973 Decimal expansion of the surface area of a triakis icosahedron with unit shorter edge length. %C A378973 The triakis icosahedron is the dual polyhedron of the truncated dodecahedron. %H A378973 Paolo Xausa, <a href="/A378973/b378973.txt">Table of n, a(n) for n = 2..10000</a> %H A378973 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TriakisIcosahedron.html">Triakis Icosahedron</a>. %H A378973 Wikipedia, <a href="https://en.wikipedia.org/wiki/Triakis_icosahedron">Triakis icosahedron</a>. %F A378973 Equals 3*sqrt((173 - 9*sqrt(5))/2) = 3*sqrt((173 - 9*A002163)/2). %e A378973 26.228595976743751681458195104356801731865266699519... %t A378973 First[RealDigits[3*Sqrt[(173 - 9*Sqrt[5])/2], 10, 100]] (* or *) %t A378973 First[RealDigits[PolyhedronData["TriakisIcosahedron", "SurfaceArea"], 10, 100]] %Y A378973 Cf. A378974 (volume), A378975 (inradius), A378976 (midradius), A378977 (dihedral angle). %Y A378973 Cf. A377694 (surface area of a truncated dodecahedron with unit edge length). %Y A378973 Cf. A002163. %K A378973 nonn,cons,easy %O A378973 2,1 %A A378973 _Paolo Xausa_, Dec 13 2024