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 A008841 #19 Jan 04 2021 20:03:07 %S A008841 0,1,0,1,0,1,12,31,0,570361,1441440,207648650161,0 %N A008841 Number of self-dual Boolean functions of n variables with transitive symmetry group. %H A008841 <a href="/index/Bo#Boolean">Index entries for sequences related to Boolean functions</a> %K A008841 nonn,hard,more %O A008841 0,7 %A A008841 _Daniel E. Loeb_