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 A100120 #3 Mar 30 2012 17:38:59 %S A100120 1,6,0,4,6,5,1,2,1,8,4,1,0,0,5,5,8,2,7,9,8,3,8,6,6,5,1,1,0,1,5,1,7,3, %T A100120 3,9,8,8,0,8,6,4,9,7,5,4,6,9,9,5,8,0,3,4,0,4,8,4,5,7,2,7,2,8,3,2,7,1, %U A100120 1,4,9,2,5,5,9,9,5,4,0,0,5,3,7,9,9,1,7,5,6,0,1,9,9,0,6,5,5,9,8,2 %N A100120 Limit of the power tower t(2)^(t(3)^(t(5)^(t(7)^(...)))) with t(n)=n!^(1/n!) and n taking prime values. %C A100120 Let f(n)=n!^(1/n!). Then this number is f(2)^(f(3)^(f(5)^(...))) %e A100120 1.604651218410055827983866511015173398808649754699580... %o A100120 (PARI) default(realprecision,100):t=1:forstep(n=100,1,-1,t=(prime(n)!^(1/prime(n)!))^t):return(t) %Y A100120 Cf. A077589, A077590, A073243, A098454, A098584. %K A100120 cons,nonn %O A100120 1,2 %A A100120 Mark Hudson (mrmarkhudson(AT)hotmail.com), Nov 09 2004 %E A100120 Offset corrected by _R. J. Mathar_, Feb 05 2009