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 A263864 #26 Sep 04 2022 17:02:11 %S A263864 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, %T A263864 1,14512,2075,328,64,14,4,1,1,163341,17316,2159,331,64,14,4,1,1, %U A263864 2360719,186173,17801,2175,332,64,14,4,1,1,43944974,2594568,189406,17885,2178,332,64,14,4,1,1,1055019099,47041877 %N 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. %C A263864 Multiset transformation of A000608. %H A263864 Alois P. Heinz, <a href="/A263864/b263864.txt">Rows n = 1..16, flattened</a> %H A263864 FindStat - Combinatorial Statistic Finder, <a href="http://www.findstat.org/StatisticsDatabase/St000181">The number of connected components of the Hasse diagram for the poset</a>. %H A263864 Salah Uddin Mohammad, Md. Shah Noor, and Md. Rashed Talukder, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL25/Uddin/uddin6.html">An Exact Enumeration of the Unlabeled Disconnected Posets</a>, J. Int. Seq., Vol. 25 (2022), Article 22.5.4. %H A263864 Wikipedia, <a href="https://en.wikipedia.org/wiki/Hasse_diagram">Hasse diagram</a> %H A263864 <a href="/index/Pos#posets">Index entries for sequences related to posets</a> %e A263864 Triangle begins: %e A263864 1; %e A263864 1, 1; %e A263864 3, 1, 1; %e A263864 10, 4, 1, 1; %e A263864 44, 13, 4, 1, 1; %e A263864 ... %Y A263864 Cf. A000112 (row sums), A000608 (k=1). %K A263864 nonn,tabl %O A263864 1,4 %A A263864 _Christian Stump_, Oct 28 2015 %E A263864 More terms from _R. J. Mathar_, Jul 12 2020