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 A088454 #20 Feb 16 2025 08:32:51 %S A088454 6,6,3,7,0,0,8,0,4,6,1,3,8,5,3,4,6,0,7,2,1,4,3,1,6,5,7,6,1,7,0,4,8,6, %T A088454 9,1,3,5,8,3,9,5,7,9,6,7,7,4,8,0,8,3,8,7,2,0,6,2,0,0,9,9,0,2,8,6,6,1, %U A088454 3,0,2,3,1,0,1,9,6,6,4,7,7,5,0,3,3,2,2,0,4,1,0,4,6,0,3,6,6,3,9,5,0,7 %N A088454 Decimal expansion of 6/(Catalan*Pi^2). %C A088454 This is the probability that a randomly chosen Gaussian integer (e.g., -2 + 5i) is squarefree (Pegg, 2003). - _Alonso del Arte_, Dec 20 2013 %C A088454 The probability that two randomly selected Gaussian integers are relatively prime (Collins and Johnson, 1989). - _Amiram Eldar_, Nov 24 2023 %H A088454 G. C. Greubel, <a href="/A088454/b088454.txt">Table of n, a(n) for n = 0..10000</a> %H A088454 George E. Collins and Jeremy R. Johnson, <a href="https://doi.org/10.1007/3-540-51084-2_23">The probability of relative primality of Gaussian integers</a>, Symbolic and Algebraic Computation: International Symposium ISSAC'88 Rome, Italy, July 4-8, 1988 Proceedings, Springer Berlin Heidelberg, 1989, pp. 252-258. %H A088454 Ed Pegg Jr., <a href="http://www.mathpuzzle.com/MAA/02-Mobius%20Function/mathgames_11_03_03.html">The Moebius Function</a>, 2003. %H A088454 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GaussianInteger.html">Gaussian Integer</a>. %H A088454 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RelativelyPrime.html">Relatively Prime</a>. %H A088454 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Squarefree.html">Squarefree</a>. %e A088454 0.663700804613853460721431657617048691358... %t A088454 RealDigits[(6/Pi^2)/Catalan, 10, 100][[1]] (* _Alonso del Arte_, Dec 20 2013 *) %o A088454 (PARI) 6/(Catalan*Pi^2) \\ _G. C. Greubel_, Aug 23 2018 %o A088454 (Magma) R:= RealField(100); 6/(Catalan(R)*Pi(R)^2); // _G. C. Greubel_, Aug 23 2018 %Y A088454 Cf. A059956, A006752. %K A088454 nonn,cons,easy %O A088454 0,1 %A A088454 _Eric W. Weisstein_, Sep 30 2003