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 A363438 #7 Feb 07 2025 13:44:09 %S A363438 2,7,8,5,1,6,3,8,6,3,1,2,2,6,2,2,9,6,7,2,9,2,5,5,4,9,1,2,7,3,5,9,4,6, %T A363438 9,8,7,8,9,9,3,2,1,7,7,2,0,7,6,3,3,1,9,9,2,6,3,7,0,2,4,1,4,7,4,1,6,2, %U A363438 5,5,1,5,0,3,2,9,1,0,6,4,9,3,0,9,4,4,4,8,5,1,3,4,7,6,6,4,8,0,8,8,0,6,5,4,2 %N A363438 Decimal expansion of the volume of the regular dodecahedron inscribed in the unit-radius sphere. %H A363438 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RegularDodecahedron.html">Regular Dodecahedron</a>. %H A363438 Wikipedia, <a href="https://en.wikipedia.org/wiki/Regular_dodecahedron">Regular dodecahedron</a>. %H A363438 <a href="/index/Al#algebraic_04">Index entries for algebraic numbers, degree 4</a>. %F A363438 Equals 2*sqrt(5+sqrt(5))/(3*sqrt(3)). %F A363438 Equals 4*(phi+2)/(3*sqrt(3)), where phi is the golden ratio (A001622). %F A363438 Equals A102769 / A179296 ^ 3. %e A363438 2.78516386312262296729255491273594698789932177207633... %t A363438 RealDigits[(2*(5 + Sqrt[5]))/(3*Sqrt[3]), 10, 120][[1]] %o A363438 (PARI) 2*sqrt(5+sqrt(5))/sqrt(27) \\ _Charles R Greathouse IV_, Feb 07 2025 %Y A363438 Cf. A118273 (cube), A122553 (regular octahedron), A339259 (regular icosahedron), A363437 (regular tetrahedron). %Y A363438 Cf. A001622. %Y A363438 Other constants related to the regular dodecahedron: A102769, A131595, A179296, A232810, A237603, A239798, A341906. %K A363438 nonn,cons %O A363438 1,1 %A A363438 _Amiram Eldar_, Jun 02 2023