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 A377698 #14 Nov 21 2024 07:42:16 %S A377698 2,5,2,3,2,0,6,0,1,1,7,0,3,7,9,0,7,6,7,3,2,9,5,7,5,0,9,5,4,7,9,2,9,2, %T A377698 2,4,0,1,0,6,2,3,6,3,5,6,9,1,9,5,1,7,6,5,9,3,3,5,5,6,8,4,1,4,0,7,6,2, %U A377698 6,7,9,1,0,4,2,9,0,1,2,0,8,1,5,5,5,6,0,2,0,1 %N A377698 Decimal expansion of 30*arcsin(sqrt(5)/3). %C A377698 Dehn invariant of a regular icosahedron with unit edge length and (negated) of a truncated dodecahedron with unit edge length. %H A377698 Brady Haran and Daniel Litt, <a href="https://www.youtube.com/watch?v=eYfpSAxGakI">The Dehn Invariant</a>, Numberphile YouTube video, 2019. %H A377698 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DehnInvariant.html">Dehn Invariant</a>. %H A377698 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RegularIcosahedron.html">Regular Icosahedron</a>. %H A377698 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TruncatedDodecahedron.html">Truncated Dodecahedron</a>. %H A377698 Wikipedia, <a href="https://en.wikipedia.org/wiki/Dehn_invariant">Dehn Invariant</a>. %H A377698 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %F A377698 Equals 30*arccos(2/3) = 30*A228496. %e A377698 25.232060117037907673295750954792922401062363569... %t A377698 First[RealDigits[30*ArcCos[2/3], 10, 100]] (* or *) %t A377698 First[RealDigits[PolyhedronData["Icosahedron", "DehnInvariant"], 10, 100]] %o A377698 (PARI) 30*acos(2/3) \\ _Charles R Greathouse IV_, Nov 21 2024 %Y A377698 Cf. A228496. %K A377698 nonn,cons,easy %O A377698 2,1 %A A377698 _Paolo Xausa_, Nov 05 2024