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 A048143 #41 May 24 2018 02:36:13 %S A048143 1,1,1,5,84,6348,7743728,2414572893530,56130437190053299918162 %N A048143 Number of labeled connected simplicial complexes with n nodes. %C A048143 Also number of connected antichains on a labeled n-set. %H A048143 Patrick De Causmaecker, Stefan De Wannemacker, <a href="http://arxiv.org/abs/1407.4288">On the number of antichains of sets in a finite universe</a>, arXiv:1407.4288 [math.CO], 2014. %H A048143 Greg Huber, <a href="/A048143/a048143.pdf">Letters to N. J. A. Sloane, May 1983</a> [Annotated, corrected, scanned copy] %H A048143 Gus Wiseman, <a href="http://www.mathematica-journal.com/2017/12/every-clutter-is-a-tree-of-blobs/">Every Clutter Is a Tree of Blobs</a>, The Mathematica Journal, Vol. 19, 2017. %H A048143 Gus Wiseman, <a href="/A048143/a048143_4.txt">Sequences enumerating clutters, antichains, hypertrees, and hyperforests, organized by labeling, spanning, and allowance of singletons</a>. %e A048143 For n=3 we could have 2 edges (in 3 ways), 3 edges (1 way), or 3 edges and a triangle (1 way), so a(3)=5. %e A048143 a(5) = 1+75+645+1655+2005+1345+485+115+20+2 = 6348. %Y A048143 Cf. A094033, A094034, A094035, A094036, A094037. %Y A048143 Cf. A000666, A006126, A030019, A054921, A120338, A275307, A285572. %K A048143 nonn,nice,more %O A048143 0,4 %A A048143 _Greg Huber_, May 12 1983 %E A048143 More terms from _Vladeta Jovovic_, Jun 17 2006 %E A048143 Entry revised by _N. J. A. Sloane_, Jul 27 2006