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 A115603 #22 Aug 29 2022 21:42:16 %S A115603 1,10,14,30 %N A115603 My teacher gave this as a "riddle". %C A115603 Possibly a version of A116955? - _Arkadiusz Wesolowski_, Mar 16 2011 %K A115603 nonn,unkn %O A115603 0,2 %A A115603 Len Burman (lburman6(AT)comcast.net), Mar 13 2006