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 A304911 #6 May 21 2018 11:26:14
%S A304911 1,0,1,4,32,351,5057,90756,1956971,49366904,1427680932,46590895869,
%T A304911 1694163054597,67938488277050,2978980898086377,141801848209013050,
%U A304911 7282651452378019772,401410357608479625207,23635996827115264290005
%N A304911 Number of labeled hyperforests spanning n vertices without singleton edges.
%F A304911 E.g.f.: exp(A030019(x) - x - 1) where A030019(x) is the e.g.f. of A030019.
%e A304911 The a(3) = 4 hyperforests are {{1,2,3}}, {{1,3},{2,3}}, {{1,2},{2,3}}, {{1,2},{1,3}}.
%Y A304911 Cf. A006126, A030019, A035053, A048143, A054921, A134954, A134955, A134957, A144959, A293993, A293994, A304716, A304717, A304867.
%K A304911 nonn
%O A304911 0,4
%A A304911 _Gus Wiseman_, May 20 2018