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 A116506 #3 May 10 2013 12:45:45
%S A116506 0,3,169,28065,16114831,33686890209,262530190180063,
%T A116506 7717643584470877185
%N A116506 Number of singular n X n rational {0,1}-matrices with no zero rows.
%F A116506 a(n) = A055601(n) - A055165(n).
%Y A116506 Cf. A000410, A116507, A116527, A116532.
%K A116506 more,nonn
%O A116506 1,2
%A A116506 _Vladeta Jovovic_, Apr 03 2006