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 A325111 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). 6
 1, 1, 0, 1, 1, 0, 3, 2, 1, 0, 10, 7, 3, 1, 0, 56, 33, 17, 5, 1, 0, 468, 244, 101, 32, 7, 1, 0, 7123, 2792, 890, 242, 60, 9, 1, 0, 194066, 52448, 11468, 2461, 527, 97, 12, 1, 0, 9743542, 1690206, 239728, 35839, 6056, 1029, 155, 15, 1, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,7 COMMENTS Articulation vertices are also called cutpoints. These are vertices that when removed increase the component count of the graph. LINKS Eric Weisstein's World of Mathematics, Articulation Vertex EXAMPLE Triangle begins:      1;      1,    0;      1,    1,   0;      3,    2,   1,   0;     10,    7,   3,   1,  0;     56,   33,  17,   5,  1, 0;    468,  244, 101,  32,  7, 1, 0;   7123, 2792, 890, 242, 60, 9, 1, 0;   ... CROSSREFS Columns k=0..5 are A002218(n>1), A241767, A241768, A241769, A241770, A241771. Row sums are A001349. Cf. A327077. Sequence in context: A204533 A259790 A246654 * A085771 A253286 A284799 Adjacent sequences:  A325108 A325109 A325110 * A325112 A325113 A325114 KEYWORD nonn,tabl,more AUTHOR Andrew Howroyd, Sep 05 2019 STATUS approved

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Last modified April 15 10:27 EDT 2021. Contains 342977 sequences. (Running on oeis4.)