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 A019696 #24 Jul 08 2025 07:34:48 %S A019696 6,9,8,1,3,1,7,0,0,7,9,7,7,3,1,8,3,0,7,6,9,4,7,6,3,0,7,3,9,5,4,4,5,0, %T A019696 8,5,3,7,7,1,4,8,7,5,5,4,1,6,6,9,0,1,8,2,4,3,8,8,7,6,5,7,6,0,6,8,4,0, %U A019696 3,6,4,5,8,4,1,3,7,9,7,7,7,4,7,2,8,9,6,6,2,7,8,5,3,8,0,3,7,9,2 %N A019696 Decimal expansion of 2*Pi/9. %C A019696 The area of a deltoid formed by rolling a circle with radius 1/3 inside a unit-radius circle. - _Amiram Eldar_, Nov 16 2021 %C A019696 Volume shared by a sphere of radius 1 inscribed in a cube and one of the six pyramids inscribed in the cube. - _Omar E. Pol_, Sep 01 2024 %H A019696 Ivan Panchenko, <a href="/A019696/b019696.txt">Table of n, a(n) for n = 0..1000</a> %H A019696 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Deltoid.html">Deltoid</a>. %H A019696 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %e A019696 0.69813170079773183076947630739544508537714875541669... %t A019696 RealDigits[(2*Pi)/9,10,120][[1]] (* _Harvey P. Dale_, Aug 24 2013 *) %o A019696 (PARI) 2*Pi/9 \\ _Michel Marcus_, Nov 16 2021 %Y A019696 Equals twice A019676. %K A019696 nonn,cons %O A019696 0,1 %A A019696 _N. J. A. Sloane_