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 A232812 #23 Jul 29 2024 15:02:37 %S A232812 7,2,0,5,6,2,1,7,3,1,0,5,6,0,1,6,3,6,0,0,5,2,7,9,2,3,2,4,0,9,7,2,5,7, %T A232812 0,7,7,7,9,0,4,4,4,5,0,9,3,5,5,8,9,3,3,5,0,1,1,0,2,2,8,3,4,2,6,9,5,2, %U A232812 3,3,6,2,4,1,1,4,5,6,7,5,1,6,2,6,8,4,5,0,7,3,0,2,1,8,5,2,1,5,7,8,6,0,9,1,7 %N A232812 Decimal expansion of the surface index of a regular tetrahedron. %C A232812 Equivalently, the surface area of a regular tetrahedron with unit volume. Among Platonic solids, surface indices decrease with increasing number of faces: this one, 6.0 (cube = hexahedron), A232811 (octahedron), A232810 (dodecahedron), and A232809 (icosahedron). %H A232812 Stanislav Sykora, <a href="/A232812/b232812.txt">Table of n, a(n) for n = 1..1000</a> %H A232812 Wikipedia, <a href="http://en.wikipedia.org/wiki/Platonic_solid">Platonic solid</a>. %H A232812 <a href="/index/Al#algebraic_06">Index entries for algebraic numbers, degree 6</a> %F A232812 Equals 2*sqrt(3)*3^(2/3). %F A232812 Equals A002194/A020829^(2/3). %e A232812 7.20562173105601636005279232409725707779044450935589335... %t A232812 RealDigits[2*Sqrt[3]*3^(2/3), 10, 120][[1]] (* _Amiram Eldar_, May 25 2023 *) %o A232812 (PARI) sqrtn(139968,6) \\ _Charles R Greathouse IV_, Apr 25 2016 %Y A232812 Cf. A002194, A020829, A232808 (surface index of a sphere), A232809, A232810, A232811. %K A232812 nonn,cons,easy %O A232812 1,1 %A A232812 _Stanislav Sykora_, Dec 01 2013