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A325329
Number of integer partitions of n whose multiplicities appear with distinct multiplicities.
6
1, 1, 2, 3, 4, 4, 8, 7, 13, 18, 25, 30, 52, 57, 81, 109, 140, 167, 230, 267, 354, 428, 532, 630, 815, 942, 1166, 1385, 1695, 1966, 2440, 2810, 3422, 4008, 4828, 5630, 6847, 7905, 9527, 11135, 13340, 15498, 18636, 21591, 25769, 30086, 35630, 41379, 49150, 56880
OFFSET
0,3
COMMENTS
The Heinz numbers of these partitions are given by A325369.
Partitions whose parts appear with distinct multiplicities are counted by A098859, with Heinz numbers A130091.
EXAMPLE
The a(0) = 1 through a(8) = 13 partitions:
() (1) (2) (3) (4) (5) (6) (7) (8)
(11) (21) (22) (32) (33) (43) (44)
(111) (31) (41) (42) (52) (53)
(1111) (11111) (51) (61) (62)
(222) (421) (71)
(321) (3211) (431)
(2211) (1111111) (521)
(111111) (2222)
(3221)
(3311)
(4211)
(32111)
(11111111)
For example, in (4,2,1,1), the multiplicities are 1 and 2, and 2 appears 1 time while 1 appears 2 times, so (4,2,1,1) is counted under a(8).
MATHEMATICA
Table[Length[Select[IntegerPartitions[n], UnsameQ@@Length/@Split[Sort[Length/@Split[#]]]&]], {n, 0, 30}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 01 2019
STATUS
approved