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%I #33 Feb 25 2024 21:05:09
%S 1,1,0,1,0,0,1,1,0,0,3,2,1,0,0,10,7,3,1,0,0,56,33,17,5,1,0,0,468,244,
%T 101,32,7,1,0,0,7123,2792,890,242,60,9,1,0,0,194066,52448,11468,2461,
%U 527,97,12,1,0,0,9743542,1690206,239728,35839,6056,1029,155,15,1,0,0
%N Triangle read by rows: T(n,k) is the number of simple connected graphs on n unlabeled nodes with k articulation vertices, (0 <= k <= n).
%C Articulation vertices are also called cutpoints. These are vertices that when removed increase the component count of the graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ArticulationVertex.html">Articulation Vertex</a>
%e Triangle begins:
%e 1;
%e 1 0;
%e 1, 0, 0;
%e 1, 1, 0, 0;
%e 3, 2, 1, 0, 0;
%e 10, 7, 3, 1, 0, 0;
%e 56, 33, 17, 5, 1, 0, 0;
%e 468, 244, 101, 32, 7, 1, 0, 0;
%e 7123, 2792, 890, 242, 60, 9, 1, 0, 0;
%e ...
%Y Columns k=0..5 are A002218(n>1), A241767, A241768, A241769, A241770, A241771.
%Y Row sums are A001349.
%Y Cf. A327077, A370064 (labeled version).
%K nonn,tabl
%O 0,11
%A _Andrew Howroyd_, Sep 05 2019
%E Diagonal for k = n inserted by _Andrew Howroyd_, Feb 25 2024
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