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 A099878 #7 Jul 29 2015 04:26:00 %S A099878 1,5,8,4,5,4,1,7,0,9,9,0,5,5,6,5,0,0,2,5,0,9,1,2,5,4,5,0,5,5,2,6,2,9, %T A099878 1,7,2,9,4,8,9,4,7,5,0,7,8,0,5,9,2,3,2,9,1,5,0,2,0,2,4,9,3,6,5,8,9,6, %U A099878 3,0,0,6,1,9,8,9,2,6,0,8,4,0,2,6,4,8,9,1,2,2,8,5,0,7,7,2,3,8,4,9,9,7,9,6 %N A099878 Decimal expansion of a nested radical: Sqrt(1 + CubeRoot(2 + 4thRoot(3 + 5thRoot(4 + ... %e A099878 1.58454170990556500250912545055... %t A099878 k = 43; r = 44; While[k > 0, r = (k + r)^(1/(k + 1)); k-- ]; RealDigits[r, 10, 111][[1]] (* _Robert G. Wilson v_, Nov 04 2004 *) %o A099878 (PARI) t=0;forstep(n=100,1,-1,t=(t+n)^(1/(n+1)));print(t) %Y A099878 Cf. A072449, A099874, A099876, A099877 for other nested radicals. %K A099878 cons,easy,nonn %O A099878 1,2 %A A099878 Mark Hudson (mrmarkhudson(AT)hotmail.com), Nov 03 2004