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 A099018 #30 Dec 22 2018 16:20:18 %S A099018 1,4,10,22,46,94,190,382,766,1534,3070,6142,12286,24574,49150,98302, %T A099018 196606,393214,786430,1572862,3145726,6291454,12582910,25165822 %N A099018 Duplicate of A033484. %K A099018 dead %O A099018 0,2