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A122982 Number of distributive sublattices of the lattice of k-tuples less than the n-th partition (in Mathematica order). 3
3, 7, 12, 15, 37, 73, 31, 103, 146, 319, 731, 63, 271, 505, 1191, 1833, 4618 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

After a(18) - for partition [1^5] - the sequence continues ?, 127, 687, 1611, 4031, 2102, 8589, ?, ?, ?, ?, ?, 255.

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

For a(5), partition [2,1], the lattice consists of the 6 pairs (i,j) where 0<=i<=2 and 0<=j<=1, with (i,j) <= (i',j') iff i<=i' and j<=j'. {(2,1), (2,0), (0,1), (0,0)} is one distributive sublattice.

CROSSREFS

Cf. A122978, A122981, A122980, A080577, A074139.

Sequence in context: A096998 A317307 A122981 * A101589 A061559 A165990

Adjacent sequences:  A122979 A122980 A122981 * A122983 A122984 A122985

KEYWORD

more,nonn

AUTHOR

Franklin T. Adams-Watters, Sep 21 2006

STATUS

approved

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Last modified April 19 04:19 EDT 2019. Contains 322237 sequences. (Running on oeis4.)