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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. 0

%I

%S 1,4,25,278,5532,200589,11662671

%N 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 Cover may include multiple occurrences of a subset. Also n-rowed binary matrices with distinct rows and all row sums 4.

%H <a href="/A058790/a058790.pdf">Formula</a>

%Y Cf. A050535, A050913, A058783-A058785.

%K more,nonn

%O 1,2

%A _Vladeta Jovovic_, Nov 30 2000

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Last modified January 19 12:36 EST 2020. Contains 331049 sequences. (Running on oeis4.)