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 A304919 #5 May 21 2018 11:26:35
%S A304919 1,1,5,45,665,14153,399421,14137301,603647601,30231588689,
%T A304919 1738713049013,112976375651901,8186616300733321,654642360222892057,
%U A304919 57267075701210437229,5440407421313402397541,557802495215406348358113,61393838258161429159571873,7220049654850517272144419941,903546142463635579042416518989
%N A304919 Number of labeled hyperforests spanning {1,...,n} and allowing singleton edges.
%F A304919 Inverse binomial transform of A134956.
%e A304919 The a(2) = 5 hyperforests are the following:
%e A304919 {{1,2}}
%e A304919 {{1},{2}}
%e A304919 {{1},{1,2}}
%e A304919 {{2},{1,2}}
%e A304919 {{1},{2},{1,2}}
%Y A304919 Cf. A030019, A035053, A048143, A134954, A134955, A134956, A134957, A134959, A144959, A303838, A304717, A304867, A304911, A304912, A304918.
%K A304919 nonn
%O A304919 0,3
%A A304919 _Gus Wiseman_, May 21 2018