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 A227434 #12 Oct 17 2015 14:29:51 %S A227434 1,4,16,28,112,448,784,3136,12301,19684,78736,314944,551152,2204608, %T A227434 8818432,15432256,61729024,242132884,387459856 %N A227434 Duplicate of A173019. %K A227434 dead %O A227434 0,2