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 A176020 #7 Feb 19 2020 09:57:51 %S A176020 2,2,9,0,9,9,4,4,4,8,7,3,5,8,0,5,6,2,8,3,9,3,0,8,8,4,6,6,5,9,4,1,3,3, %T A176020 2,0,3,6,1,0,9,7,3,9,0,1,7,6,3,8,6,3,6,0,8,8,6,2,5,2,4,5,8,8,7,0,4,4, %U A176020 9,4,3,6,3,9,7,8,9,9,3,0,1,1,1,7,3,0,9,5,7,9,2,2,8,6,2,2,4,5,0,5,9,7,2,1,0 %N A176020 Decimal expansion of (3+sqrt(15))/3. %C A176020 Continued fraction expansion of (3+sqrt(15))/3 is A010693. %C A176020 a(n) = A020817(n-1) for n > 1; a(1) = 2. %H A176020 Daniel Starodubtsev, <a href="/A176020/b176020.txt">Table of n, a(n) for n = 1..10000</a> %e A176020 (3+sqrt(15))/3 = 2.29099444873580562839... %t A176020 RealDigits[(3+Sqrt[15])/3,10,120][[1]] (* _Harvey P. Dale_, May 20 2013 *) %Y A176020 Cf. A010472 (decimal expansion of sqrt(15)), A176016 (decimal expansion of (3+sqrt(15))/6), A010693 (repeat 2, 3), A020817 (decimal expansion of 1/sqrt(60)). %K A176020 cons,nonn %O A176020 1,1 %A A176020 _Klaus Brockhaus_, Apr 06 2010