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A058792 Number of covers of an unlabeled n-set such that every point of the set is covered by exactly 5 subsets of the cover and that intersection of every 5 subsets of the cover contains at most one point. 1
1, 5, 44, 966, 53535, 7043925, 1775617861, 738134963014, 461550358993886, 409321620633426443 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Cover may include multiple occurrences of a subset. Also n-rowed binary matrices with distinct rows and all row sums 5.

LINKS

Table of n, a(n) for n=1..10.

Vladeta Jovovic, Formula

CROSSREFS

Row n=5 of A331508.

Cf. A050535, A050913, A058783, A058784, A058785.

Sequence in context: A301655 A048940 A218375 * A113948 A215517 A215584

Adjacent sequences:  A058789 A058790 A058791 * A058793 A058794 A058795

KEYWORD

more,nonn

AUTHOR

Vladeta Jovovic, Nov 30 2000

EXTENSIONS

a(7)-a(10) from Andrew Howroyd, Jan 29 2020

STATUS

approved

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Last modified February 16 16:00 EST 2020. Contains 331961 sequences. (Running on oeis4.)