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 A080991 #2 Mar 31 2012 10:29:02 %S A080991 4,19,421,203461,46882572661,2460798973136286293701, %T A080991 6713425293781487374296340087251890561890261, %U A080991 49548081347487610687284649853537701683093220643723475323834248591924587627064854208741 %N A080991 Ratios of successive terms of A080989. %Y A080991 Cf. A080989, A080582, A080987. %K A080991 nonn %O A080991 1,1 %A A080991 _Hugo Pfoertner_, Feb 26 2003