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 A075429 #3 Mar 30 2012 18:50:26 %S A075429 2,8,7,494764640798827359861461484,2016,44,1914, %T A075429 28763295962709272528037893195870015938157927816600800, %U A075429 135182360017670059436612452 %N A075429 First integer reached when starting with 1+2/(n*(n+1)) and iterating the map x -> x*ceiling(x) A075428(n) times, or -1 if no integer is ever reached. %e A075429 n=5: after A075428(5)=4 steps 1+2/(5*6)=1+1/15=16/15 -> 32/15 -> 32/5 -> 224/5 -> 2016, therefore a(5)=2016. %K A075429 nonn %O A075429 1,1 %A A075429 _Reinhard Zumkeller_, Sep 16 2002