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#19 by Alois P. Heinz at Mon Jan 11 15:11:01 EST 2021
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#18 by Michel Marcus at Mon Jan 11 14:42:28 EST 2021
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#17 by Andrew Howroyd at Mon Jan 11 13:57:05 EST 2021
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#16 by Andrew Howroyd at Mon Jan 11 13:15:35 EST 2021
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| LINKS
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Andrew Howroyd, <a href="/A245797/b245797.txt">Table of n, a(n) for n = 1..50</a>
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| STATUS
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approved
editing
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#15 by Susanna Cuyler at Wed Sep 11 20:21:19 EDT 2019
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#14 by Gus Wiseman at Wed Sep 11 17:31:35 EDT 2019
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#13 by Gus Wiseman at Wed Sep 11 17:30:48 EDT 2019
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| FORMULA
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Binomial transform of A327227 (assuming a(0) = 0).
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#12 by Gus Wiseman at Wed Sep 11 16:59:24 EDT 2019
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| MATHEMATICA
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Table[Length[Select[Subsets[Subsets[Range[n], {2}]], Min@@Length/@Split[Sort[Join@@#]]==1&]], {n, 0, 5}] (* Gus Wiseman, Sep 11 2019 *)
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| CROSSREFS
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The covering case is A327227.
The connected case is A327362.
The generalization to set-systems is A327228.
BII-numbers of set-systems with minimum degree 1 are A327105.
Cf. A001187, A006129, A059166, A059167, A100743, A136284, A327079, A327098, A327103, A327229, A327230.
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| STATUS
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approved
editing
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#11 by Peter Luschny at Sat Feb 23 07:23:48 EST 2019
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#10 by Jean-François Alcover at Sat Feb 23 06:18:14 EST 2019
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