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 A386412 #8 Jul 21 2025 11:39:24 %S A386412 1,4,2,5,8,3,3,0,2,4,9,1,9,7,7,0,2,4,0,7,9,2,8,4,0,1,2,1,9,7,8,8,1,7, %T A386412 0,3,8,5,1,2,8,2,3,4,1,4,9,7,6,7,4,7,4,0,8,2,3,6,2,7,4,5,3,6,6,4,3,7, %U A386412 5,6,4,6,0,9,9,0,7,2,0,0,2,4,1,0,2,7,4,5,0,2 %N A386412 Decimal expansion of the surface area of an augmented truncated tetrahedron with unit edge. %C A386412 The augmented truncated tetrahedron is Johnson solid J_65. %H A386412 Paolo Xausa, <a href="/A386412/b386412.txt">Table of n, a(n) for n = 2..10000</a> %H A386412 Wikipedia, <a href="https://en.wikipedia.org/wiki/Augmented_truncated_tetrahedron">Augmented truncated tetrahedron</a>. %F A386412 Equals 3 + 13*sqrt(3)/2 = 3 + 13*A010527. %F A386412 Equals the largest root of 4*x^2 - 24*x - 471. %e A386412 14.258330249197702407928401219788170385128234149767... %t A386412 First[RealDigits[3 + 13*Sqrt[3]/2, 10, 100]] (* or *) %t A386412 First[RealDigits[PolyhedronData["J65", "SurfaceArea"], 10, 100]] %Y A386412 Cf. A386411 (volume). %Y A386412 Cf. A010527. %K A386412 nonn,cons,easy %O A386412 2,2 %A A386412 _Paolo Xausa_, Jul 21 2025