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 A046997 #6 Mar 07 2020 07:24:59 %S A046997 0,1,1,9,33,187,847,4911,25849 %N A046997 Number of Baxter permutations: A001183/2. %K A046997 nonn,more %O A046997 1,4 %A A046997 _N. J. A. Sloane_