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 A379890 #9 Feb 10 2025 11:56:01 %S A379890 3,4,9,9,5,2,7,8,4,8,9,0,5,7,6,4,0,8,2,5,7,5,3,9,3,9,0,0,3,3,7,8,9,8, %T A379890 2,7,8,7,7,5,8,4,9,3,6,8,9,5,0,8,8,9,3,2,5,7,3,4,2,8,9,2,2,9,7,7,1,4, %U A379890 6,5,2,5,8,0,6,9,1,2,6,3,1,0,8,6,3,0,3,1,9,6 %N A379890 Decimal expansion of the inradius of a pentagonal hexecontahedron with unit shorter edge length. %C A379890 The pentagonal hexecontahedron is the dual polyhedron of the snub dodecahedron. %H A379890 Paolo Xausa, <a href="/A379890/b379890.txt">Table of n, a(n) for n = 1..10000</a> %H A379890 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PentagonalHexecontahedron.html">Pentagonal Hexecontahedron</a>. %H A379890 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentagonal_hexecontahedron">Pentagonal hexecontahedron</a>. %H A379890 <a href="/index/Al#algebraic_12">Index entries for algebraic numbers, degree 12</a>. %F A379890 Equals the largest real root of 856064*x^12 - 11107328*x^10 + 7691264*x^8 - 698816*x^6 + 8816*x^4 - 440*x^2 + 1. %e A379890 3.49952784890576408257539390033789827877584936895... %t A379890 First[RealDigits[Root[856064*#^12 - 11107328*#^10 + 7691264*#^8 - 698816*#^6 + 8816*#^4 - 440*#^2 + 1 &, 8], 10, 100]] (* or *) %t A379890 First[RealDigits[PolyhedronData["PentagonalHexecontahedron", "Inradius"], 10, 100]] %Y A379890 Cf. A379888 (surface area), A379889 (volume), A379891 (midradius), A379892 (dihedral angle). %K A379890 nonn,cons,easy %O A379890 1,1 %A A379890 _Paolo Xausa_, Jan 07 2025