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A005748 Number of n-covers of a 7-set.
(Formerly M5098)
18
1, 20, 348, 6093, 108182, 1890123, 31500927, 490890277, 7086257602, 94548676765, 1167995082810, 13406707973018, 143598707530374, 1441525802509250, 13619352767824724, 121574625625030584 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

R. J. Clarke, Covering a set by subsets, Discrete Math., 81 (1990), 147-152.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=1..16.

Vladeta Jovovic, Binary matrices up to row and column permutations

CROSSREFS

Cf. A005744-A005747, A005783-A005786, A055066.

Sequence in context: A167031 A268787 A272183 * A230236 A093144 A285393

Adjacent sequences:  A005745 A005746 A005747 * A005749 A005750 A005751

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Simon Plouffe

EXTENSIONS

Corrected and extended by Vladeta Jovovic, Jun 13 2000

STATUS

approved

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Last modified January 25 01:39 EST 2020. Contains 331229 sequences. (Running on oeis4.)