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 A058791 #12 Aug 26 2022 18:50:23 %S A058791 1,4,25,278,5532,200589,11662671,981458725,111213730857, %T A058791 16212510876591,2947663429595884,653299790376494253, %U A058791 173373367472722467460,54295204354760461199529,19822683467350158062736540 %N A058791 Number of covers of an unlabeled n-set such that every point of the set is covered by exactly 4 subsets of the cover and that intersection of every 4 subsets of the cover contains at most one point. %C A058791 Cover may include multiple occurrences of a subset. Also n-rowed binary matrices with distinct rows and all row sums 4. %H A058791 Vladeta Jovovic, <a href="/A058790/a058790.pdf">Formula</a> %Y A058791 Row n=4 of A331508. %Y A058791 Cf. A050535, A050913, A058783, A058784, A058785. %K A058791 more,nonn %O A058791 1,2 %A A058791 _Vladeta Jovovic_, Nov 30 2000 %E A058791 a(8)-a(12) from _Andrew Howroyd_, Jan 29 2020 %E A058791 a(13)-a(15) from _Sean A. Irvine_, Aug 26 2022