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 A077893 #9 Sep 14 2023 04:22:14 %S A077893 1,1,1,1,3,3,5,5,11,11,21,21,43,43,85,85,171,171,341,341,683,683,1365, %T A077893 1365 %N A077893 Duplicate of A077953. %K A077893 dead %O A077893 0,5