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 A327805 #12 Dec 27 2020 03:34:43
%S A327805 1,1,0,2,1,0,4,2,1,0,11,6,3,1,0,34,21,10,3,1,0,156,112,56,17,4,1,0,
%T A327805 1044,853,468,136,25,4,1,0,12346,11117,7123,2388,384,39,5,1,0,274668,
%U A327805 261080,194066,80890,14480,1051,59,5,1,0,12005168,11716571,9743542,5114079,1211735,102630,3211,87,6,1,0
%N A327805 Triangle read by rows where T(n,k) is the number of unlabeled simple graphs with n vertices and vertex-connectivity >= k.
%C A327805 The vertex-connectivity of a graph is the minimum number of vertices that must be removed (along with any incident edges) to obtain a non-connected graph or singleton. Note that this means a single node has vertex-connectivity 0.
%H A327805 Gus Wiseman, <a href="/A327805/a327805.png">The graphs counted in row n = 4 (isolated vertices not shown).</a>
%F A327805 T(n,k) = Sum_{j=k..n} A259862(n,j).
%e A327805 Triangle begins:
%e A327805 1
%e A327805 1 0
%e A327805 2 1 0
%e A327805 4 2 1 0
%e A327805 11 6 3 1 0
%e A327805 34 21 10 3 1 0
%Y A327805 Row-wise partial sums of A259862.
%Y A327805 The labeled version is A327363.
%Y A327805 The covering case is A327365, from which this sequence differs only in the k = 0 column.
%Y A327805 Column k = 0 is A000088 (graphs).
%Y A327805 Column k = 1 is A001349 (connected graphs), if we assume A001349(0) = A001349(1) = 0.
%Y A327805 Column k = 2 is A002218 (2-connected graphs), if we assume A002218(2) = 0.
%Y A327805 The triangle for vertex-connectivity exactly k is A259862.
%Y A327805 Cf. A326786, A327051, A327114, A327125, A327126, A327127, A327334.
%K A327805 nonn,tabl
%O A327805 0,4
%A A327805 _Gus Wiseman_, Sep 26 2019
%E A327805 Terms a(21) and beyond from _Andrew Howroyd_, Dec 26 2020