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 A067496 #14 Dec 11 2020 19:22:30 %S A067496 1,18,20,22,41,43,62,64,66,83,85,87,106,108,110,127,129,131,150,152, %T A067496 171,173,175,194,196,215,217,219,236,238,240 %N A067496 Duplicate of A054565. %K A067496 dead %O A067496 1,2