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 A080302 #5 Jan 11 2024 10:53:07 %S A080302 1,3,3,27,27,27,9,567,567,567,567,891,891,297,297 %N A080302 a(n) = A080292(n)/3. %K A080302 nonn,more %O A080302 1,2 %A A080302 _Antti Karttunen_, Mar 02 2003