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 A382658 #25 Apr 10 2025 08:49:25
%S A382658 1,2,6,56,15026,1746994454,1235642810043131384,
%T A382658 40822119528659637193235146998172,
%U A382658 374299843632760183014518932671883409448485124695664,7237131063359733682672812567239149471890797777405500679038631641915376539420
%N A382658 Number of forknesses on n elements.
%C A382658 Forknesses are sets of triples over the set {1,...,n} satisfying certain combinatorial axioms; see Chvátal-Matúš-Zwólš.
%H A382658 T. Boege, <a href="https://taboege.de/blog/2025/02/Counting-combinatorial-objects-using-SAT-solvers/">Counting combinatorial objects using SAT solvers</a>.
%H A382658 V. Chvátal, F. Matúš, and Y. Zwólš, <a href="https://arxiv.org/abs/1608.03949">Patterns of conjunctive forks</a>, arXiv:1608.03949 [math.PR], 2016.
%H A382658 F. Matúš, <a href="https://doi.org/10.1007/s10474-018-0799-6">On patterns of conditional independences and covariance signs among binary variables</a>, Acta Math. Hungar. 154, 511-524 (2018).
%e A382658 For n=2 the a(2)=6 forknesses are {}, {111}, {222}, {111, 222}, {111, 112, 122, 211, 221, 222}, and {111, 112, 121, 122, 211, 212, 221, 222}.
%o A382658 (Perl) # see Boege link.
%K A382658 nonn
%O A382658 0,2
%A A382658 _Tobias Boege_, Apr 02 2025