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 A351157 #12 Mar 11 2022 14:36:42 %S A351157 1,2,4,11,33,145,839,7449 %N A351157 Number of symmetric 0-1 matrices with zero main diagonal where rows are sorted lexicographically and row sums are nondecreasing. %Y A351157 Cf. A016121 %K A351157 nonn,hard,more %O A351157 1,2 %A A351157 _Max Alekseyev_, Feb 02 2022