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 A352801 #8 Apr 08 2022 00:52:47 %S A352801 1,1,2,4,16,170,360,840,82320,181440,1512000,19958400,79833600, %T A352801 259459200,14529715200 %N A352801 Number of symmetric n X n 01-matrices with maximum number of 1s and no 2 X 2 all-1 submatrix. %F A352801 a(n) is the last element in the n-th row of triangle A350189. %F A352801 Conjecture: the maximum number of 1s equals A072567(n), and so a(n) = A350189(n, A072567(n)). %Y A352801 Cf. A072567, A191874, A191966, A335820, A350189, A351335, A352258. %K A352801 nonn,more %O A352801 0,3 %A A352801 _Max Alekseyev_, Apr 03 2022