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 A263864 Triangle read by rows: T(n,k) (n>=1, k>=1) is the number of posets with n elements whose Hasse diagram has k connected components. 5
 1, 1, 1, 3, 1, 1, 10, 4, 1, 1, 44, 13, 4, 1, 1, 238, 60, 14, 4, 1, 1, 1650, 312, 63, 14, 4, 1, 1, 14512, 2075, 328, 64, 14, 4, 1, 1, 163341, 17316, 2159, 331, 64, 14, 4, 1, 1, 2360719, 186173, 17801, 2175, 332, 64, 14, 4, 1, 1, 43944974, 2594568, 189406, 17885, 2178, 332, 64, 14, 4, 1, 1, 1055019099, 47041877 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Multiset transformation of A000608. LINKS FindStat - Combinatorial Statistic Finder, The number of connected components of the Hasse diagram for the poset. Salah Uddin Mohammad, Md. Shah Noor, and Md. Rashed Talukder, An Exact Enumeration of the Unlabeled Disconnected Posets, J. Int. Seq., Vol. 25 (2022), Article 22.5.4. Wikipedia, Hasse diagram EXAMPLE Triangle begins:    1;    1,  1;    3,  1,  1;   10,  4,  1,  1;   44, 13,  4,  1,  1;   ... CROSSREFS Cf. A000112 (row sums), A000608 (k=1). Sequence in context: A268115 A106268 A267655 * A060543 A267751 A185996 Adjacent sequences:  A263861 A263862 A263863 * A263865 A263866 A263867 KEYWORD nonn,tabl AUTHOR Christian Stump, Oct 28 2015 EXTENSIONS More terms from R. J. Mathar, Jul 12 2020 STATUS approved

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Last modified August 9 21:08 EDT 2022. Contains 356026 sequences. (Running on oeis4.)