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A122982
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Number of distributive sublattices of the lattice of k-tuples less than the n-th partition (in Mathematica order).
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3
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3, 7, 12, 15, 37, 73, 31, 103, 146, 319, 731, 63, 271, 505, 1191, 1833, 4618
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OFFSET
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1,1
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COMMENTS
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After a(18) - for partition [1^5] - the sequence continues ?, 127, 687, 1611, 4031, 2102, 8589, ?, ?, ?, ?, ?, 255.
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LINKS
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Table of n, a(n) for n=1..17.
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EXAMPLE
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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.
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CROSSREFS
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Cf. A122978, A122981, A122980, A080577, A074139.
Sequence in context: A317307 A331042 A122981 * A101589 A061559 A165990
Adjacent sequences: A122979 A122980 A122981 * A122983 A122984 A122985
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KEYWORD
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more,nonn
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AUTHOR
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Franklin T. Adams-Watters, Sep 21 2006
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STATUS
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approved
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