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 A109828 #17 Nov 03 2018 18:22:12 %S A109828 11,7,2,2131,1531,385591,16651,15514861,857095381,205528443121, %T A109828 1389122693971,216857744866621,758083947856951,107588900851484911, %U A109828 69257563144280941,3203000719597029781 %N A109828 Duplicate of A005603. %K A109828 dead %O A109828 1,1