A058792 - OEIS

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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, 5, 44, 966, 53535, 7043925, 1775617861, 738134963014, 461550358993886, 409321620633426443, 493892363593918906465

(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..11.

Vladeta Jovovic, Formula

CROSSREFS

Row n=5 of A331508.

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