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 A304918 #6 May 21 2018 11:26:28
%S A304918 1,2,5,18,104,943,12133,203038,4177755,101922814,2874725600,
%T A304918 92009680557,3294276613933,130446181101044,5660055256165565,
%U A304918 267044522107706072,13611243187516647324,745329728016955480687,43636132793651444511809,2719977663069107176768790
%N A304918 Number of labeled antichain hyperforests spanning a subset of {1,...,n}.
%F A304918 Binomial transform of A134954.
%e A304918 The a(3) = 18 hyperforests are the following:
%e A304918 {{1,2,3}} {{2,3}} {{1,3}} {{1,2}} {{3}} {{2}} {{1}} {}
%e A304918 {{1,3},{2,3}} {{2},{3}} {{1},{3}} {{1},{2}}
%e A304918 {{1,2},{2,3}}
%e A304918 {{1,2},{1,3}}
%e A304918 {{3},{1,2}}
%e A304918 {{2},{1,3}}
%e A304918 {{1},{2,3}}
%e A304918 {{1},{2},{3}}
%Y A304918 Cf. A030019, A035053, A048143, A134954, A134955, A134957, A134956, A134957, A134959, A144959, A303838, A304716, A304717, A304867, A304911, A304912.
%K A304918 nonn
%O A304918 0,2
%A A304918 _Gus Wiseman_, May 21 2018