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 A378825 #8 Dec 10 2024 05:49:06 %S A378825 1,9,5,0,6,8,1,3,3,1,7,8,4,7,5,4,8,1,6,4,8,8,7,5,9,5,1,1,0,5,6,1,0,8, %T A378825 1,6,3,1,7,0,9,8,9,6,4,2,1,1,9,3,0,4,9,1,2,4,9,1,3,0,8,5,8,1,0,4,4,7, %U A378825 9,6,5,4,2,1,8,4,0,7,4,9,7,7,1,5,7,0,0,5,1,3 %N A378825 Decimal expansion of the inradius of a pentagonal icositetrahedron with unit shorter edge length. %C A378825 The pentagonal icositetrahedron is the dual polyhedron of the snub cube. %H A378825 Paolo Xausa, <a href="/A378825/b378825.txt">Table of n, a(n) for n = 1..10000</a> %F A378825 Equals (1 + s)/(2*sqrt((1 - 2*s)*(1 - s^2))), where s = (A058265 - 1)/2. %F A378825 Equals the positive real root of 448*x^6 - 1712*x^4 + 28*x^2 - 1. %e A378825 1.9506813317847548164887595110561081631709896421193... %t A378825 First[RealDigits[Root[448*#^6 - 1712*#^4 + 28*#^2 - 1 &, 2], 10, 100]] (* or *) %t A378825 First[RealDigits[PolyhedronData["PentagonalIcositetrahedron", "Inradius"], 10, 100]] %Y A378825 Cf. A378823 (surface area), A378824 (volume), A378826 (midradius), A378827 (dihedral angle). %Y A378825 Cf. A058265. %K A378825 nonn,cons,easy %O A378825 1,2 %A A378825 _Paolo Xausa_, Dec 10 2024