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 A133279 #11 Sep 02 2017 05:37:35
%S A133279 1,0,1,1,7,21,234,2252,64420,2148355,183956671
%N A133279 Number of unlabeled mating graphs with n nodes and a degenerate adjacency matrix.
%C A133279 Mating graphs are graphs where no two nodes have the same set of neighbors.
%C A133279 Graphs with an invertible adjacency matrix are mating graphs.
%F A133279 a(n) = A004110(n) - A109717(n).
%t A133279 k = {}; For[i = 1, i < 8, i++, lg = ListGraphs[i] ; len = Length[lg]; k = Append[k, Length[Select[Range[len], Det[ToAdjacencyMatrix[lg[[ # ]]]] == 0 && Length[Union[ToAdjacencyMatrix[lg[[ # ]]]]] == i &]]]]; k
%Y A133279 Cf. A004110, A109717.
%K A133279 nonn,more
%O A133279 1,5
%A A133279 _Tanya Khovanova_, Aug 27 2008
%E A133279 a(8)-a(11) by _Shreeyash Gotmare_, Aug 28 2017