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 A377606 #9 Nov 21 2024 07:44:46 %S A377606 7,9,8,2,4,0,1,4,1,6,7,8,4,8,0,7,4,1,7,2,1,6,2,1,2,8,5,0,5,6,3,1,8,8, %T A377606 8,0,1,0,3,9,0,6,5,7,9,2,8,4,7,8,0,2,8,0,6,9,4,0,4,9,2,0,8,2,2,4,8,6, %U A377606 3,1,0,6,5,0,3,0,7,6,3,0,0,4,8,4,6,4,9,3,7,1 %N A377606 Decimal expansion of -30*arcsin((5 - 4*sqrt(5))/15). %C A377606 Dehn invariant of an icosidodecahedron with unit edge length and (negated) of a (small) rhombicosidodecahedron with unit edge length. %H A377606 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DehnInvariant.html">Dehn Invariant</a>. %H A377606 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Icosidodecahedron.html">Icosidodecahedron</a>. %H A377606 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SmallRhombicosidodecahedron.html">Small Rhombicosidodecahedron</a>. %H A377606 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %F A377606 Equals -30*arcsin((5 - 4*A002163)/15) = -30*arcsin((5 - A010532)/15). %e A377606 7.9824014167848074172162128505631888010390657928... %t A377606 First[RealDigits[-30*ArcSin[(5 - Sqrt[80])/15], 10, 100]] (* or *) %t A377606 First[RealDigits[PolyhedronData["Icosidodecahedron", "DehnInvariant"], 10, 100]] %o A377606 (PARI) 30*asin((4*sqrt(5)-5)/15) \\ _Charles R Greathouse IV_, Nov 21 2024 %Y A377606 Cf. A002163, A010532. %K A377606 nonn,cons,easy %O A377606 1,1 %A A377606 _Paolo Xausa_, Nov 03 2024