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 A319540 Number of unlabeled 3-uniform hypergraphs spanning n vertices such that every pair of vertices appears together in some block. 4
 1, 1, 0, 1, 2, 14, 964, 3908438 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS EXAMPLE Non-isomorphic representatives of the a(5) = 14 hypergraphs:               {{123}{145}{245}{345}}             {{123}{124}{135}{245}{345}}             {{123}{145}{235}{245}{345}}           {{123}{134}{145}{235}{245}{345}}           {{123}{145}{234}{235}{245}{345}}           {{124}{135}{145}{235}{245}{345}}           {{125}{135}{145}{235}{245}{345}}         {{123}{124}{135}{145}{235}{245}{345}}         {{124}{135}{145}{234}{235}{245}{345}}         {{125}{135}{145}{234}{235}{245}{345}}       {{123}{124}{135}{145}{234}{235}{245}{345}}       {{125}{134}{135}{145}{234}{235}{245}{345}}     {{124}{125}{134}{135}{145}{234}{235}{245}{345}}   {{123}{124}{125}{134}{135}{145}{234}{235}{245}{345}} CROSSREFS The labeled case is A302394. Cf. A000665, A006126, A006129, A038041, A299471, A301922, A302374, A306021, A320395, A322451. Sequence in context: A144017 A032419 A225163 * A190634 A130421 A227403 Adjacent sequences:  A319537 A319538 A319539 * A319541 A319542 A319543 KEYWORD nonn,more AUTHOR Gus Wiseman, Jan 09 2019 EXTENSIONS a(6)-a(7) from Andrew Howroyd, Aug 17 2019 STATUS approved

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Last modified September 29 21:59 EDT 2020. Contains 337432 sequences. (Running on oeis4.)