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 A116527 #6 Jan 08 2020 17:50:38
%S A116527 0,0,0,75,22365,13303500,21058940420,98692672142610
%N A116527 Number of singular n X n rational {0,1}-matrices with no zero rows or columns and with all rows distinct and all columns distinct, up to permutation of rows.
%F A116527 a(n) = A094000(n) - A088389(n).
%F A116527 Conjecture: a(n) = A000410(n) - A000409(n-1) for n>1. - _Jean-François Alcover_, Jan 08 2020
%Y A116527 Cf. A000409, A000410, A116506, A116507, A116532.
%K A116527 more,nonn
%O A116527 1,4
%A A116527 _Vladeta Jovovic_, Apr 03 2006