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 A080111 #10 Sep 20 2022 08:39:07 %S A080111 1,0,0,0,0,0,1,1,0,1,0,0,1,1,0,1,0,1,1,0,1,0,0,1,1,1,0,1,1,1,1,0,1,1, %T A080111 1,0,1,1,0,1,1,1,0,1,1,0,1,1,1,1,1,0,1,0,1,0,1,0,1,1,1,1,1,0,1,1,1,1, %U A080111 1,1,1,0,1,1,1,0,1,1,1,1,0,1,0,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,1,0,1,1 %N A080111 Characteristic function of A080113. %H A080111 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a> %p A080111 A080111 := n -> 1-A080116(A080117(n)); %K A080111 nonn %O A080111 1,1 %A A080111 _Antti Karttunen_, Feb 11 2003