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 A116532 #5 Mar 08 2018 18:50:07
%S A116532 0,0,3,285,50820,23551920,31898503077,134251404794199
%N A116532 Number of singular n X n rational {0,1}-matrices with no zero rows or columns and with all rows distinct, up to permutation of rows.
%F A116532 a(n) = A054780(n) - A088389(n).
%Y A116532 Cf. A000410, A116506, A116527.
%Y A116532 Binary matrices with distinct rows and columns, various versions: A059202, A088309, A088310, A088616, A089673, A089674, A093466, A094000, A094223, A116532, A116539, A181230, A259763
%K A116532 more,nonn
%O A116532 1,3
%A A116532 _Vladeta Jovovic_, Apr 03 2006