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On Refining Partitions
Author(s) -
Erdös P.,
Guy Richard K.,
Moon J. W.
Publication year - 1975
Publication title -
journal of the london mathematical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.441
H-Index - 62
eISSN - 1469-7750
pISSN - 0024-6107
DOI - 10.1112/jlms/s2-9.4.565
Subject(s) - citation , library science , computer science , mathematics
3. A lower bound To obtain a lower bound we count only those sequences of refinements which include the partition 1 .2.3 . . . d . r of n into d or d + 1 parts, d of which are of different size, where 0 < r = n-$d(d + 1) < d, so that J(2n) > d > J(2n)-3. Moreover we only count sequences in which we split off 1 from each of the d 1 parts of different size greater than 1. These d 1 steps can be made in (d l ) ! ways and result in the partition ldf 2 .3 . . . (d 1) .r of n into 2d 1 or 2d parts, d 1 (or possibly d ) of which are of different size. We deal with this in the same way, making splits of size 1 from each of the d-2 parts of different size greater than 1, in (d-2)! possible ways. If we continue, we see that the number of sequences of refinements is at least