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 A301481 #28 Aug 21 2019 05:31:57
%S A301481 1,1,2,4,12,58,2381,14026281,29284932065996445,
%T A301481 468863491068204425232922367150021,
%U A301481 1994324729204021501147398087008429476673379600542622915802043462326345
%N A301481 Number of unlabeled uniform hypergraphs spanning n vertices.
%C A301481 A hypergraph is uniform if all edges have the same size.
%H A301481 Alois P. Heinz, <a href="/A301481/b301481.txt">Table of n, a(n) for n = 0..14</a> (first 13 terms from Andrew Howroyd)
%e A301481 Non-isomorphic representatives of the a(4) = 12 hypergraphs:
%e A301481 {{1,2,3,4}}
%e A301481 {{1,2},{3,4}}
%e A301481 {{1},{2},{3},{4}}
%e A301481 {{1,3,4},{2,3,4}}
%e A301481 {{1,3},{2,4},{3,4}}
%e A301481 {{1,4},{2,4},{3,4}}
%e A301481 {{1,2,4},{1,3,4},{2,3,4}}
%e A301481 {{1,2},{1,3},{2,4},{3,4}}
%e A301481 {{1,4},{2,3},{2,4},{3,4}}
%e A301481 {{1,3},{1,4},{2,3},{2,4},{3,4}}
%e A301481 {{1,2,3},{1,2,4},{1,3,4},{2,3,4}}
%e A301481 {{1,2},{1,3},{1,4},{2,3},{2,4},{3,4}}
%o A301481 (PARI) \\ see A301922 for U(n,k).
%o A301481 a(n)={ if(n==0, 1, sum(k=1, n, U(n,k)-U(n-1,k))) } \\ _Andrew Howroyd_, Aug 10 2019
%Y A301481 Row sums of A301922.
%Y A301481 Cf. A003465, A038041, A055621, A298422, A301920, A306017-A306021.
%K A301481 nonn
%O A301481 0,3
%A A301481 _Gus Wiseman_, Jun 19 2018
%E A301481 Terms a(6) and beyond from _Andrew Howroyd_, Aug 09 2019