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 A244969 #24 Mar 28 2020 22:45:29 %S A244969 15,35,45,63,75,77,91,99,105,117,135,143,153,165,175,187,189,195,209, %T A244969 221,225,231,245,247,255,273,285,297,299,315,323,325,345,351,357,375, %U A244969 385,391,399,405,425 %N A244969 Duplicate of A090196. %K A244969 dead %O A244969 1,1