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 A102888 #21 Feb 16 2025 08:32:56 %S A102888 4,2,2,1,5,7,7,3,3,1,1,5,8,2,6,6,2,7,0,2,3,3,6,5,9,1,6,6,2,3,8,5,0,7, %T A102888 5,8,1,2,3,4,0,7,9,7,0,6,9,7,6,2,9,0,4,3,9,3,5,7,3,7,5,9,5,0,8,6,5,7, %U A102888 8,7,4,6,9,8,3,8,5,5,4,9,6,3,7,7,9,0,7,9,8,1,6,7,4,2,4,4,6,9,0,1,1,4 %N A102888 Decimal expansion of volume of the Reuleaux tetrahedron. %H A102888 Vincenzo Librandi, <a href="/A102888/b102888.txt">Table of n, a(n) for n = 0..5000</a> %H A102888 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DefiniteIntegral.html">Definite Integral</a> %H A102888 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ReuleauxTetrahedron.html">Reuleaux Tetrahedron</a> %F A102888 (8/3)*Pi - (27/4)*arccos(1/3) + sqrt(2)/4 %F A102888 = (3*sqrt(2) - 49*Pi + 162*arctan(sqrt(2)))/12 %F A102888 = (1/24)*(6*sqrt(2) + 16*Pi + 57*arccos(17/81) - 132*arctan(sqrt(2))). %e A102888 0.422157733... %t A102888 RealDigits[8 Pi/3 - 27 ArcSec[3]/4 + Sqrt[2]/4, 10, 102][[1]] (* _Eric W. Weisstein_, Dec 15 2017 *) %o A102888 (PARI) 8/3*Pi - (27/4)*acos(1/3) + sqrt(2)/4 \\ _Michel Marcus_, Dec 15 2017 %K A102888 nonn,cons %O A102888 0,1 %A A102888 _Eric W. Weisstein_, Jan 16 2005