A325330 Number of integer partitions of n whose multiplicities have multiplicities that cover an initial interval of positive integers.
1, 1, 2, 2, 4, 5, 7, 11, 16, 22, 31, 44, 55, 77, 96, 127, 158, 208, 251, 329, 400, 501, 610, 766, 915, 1141, 1368, 1677, 2005, 2454, 2913, 3553, 4219, 5110, 6053, 7300, 8644, 10376, 12238, 14645, 17216, 20504, 24047, 28501, 33336, 39373, 45871, 53926, 62745
Offset: 0
Keywords
Examples
The a(0) = 1 through a(8) = 16 partitions: () (1) (2) (3) (4) (5) (6) (7) (8) (11) (111) (22) (221) (33) (322) (44) (211) (311) (222) (331) (332) (1111) (2111) (411) (511) (422) (11111) (3111) (2221) (611) (21111) (3211) (2222) (111111) (4111) (3221) (22111) (4211) (31111) (5111) (211111) (22211) (1111111) (32111) (41111) (221111) (311111) (2111111) (11111111) For example, the partition (5,5,4,3,3,3,2,2) has multiplicities (2,1,3,2) with multiplicities (1,2,1) which cover the initial interval {1,2}, so (5,5,4,3,3,3,2,2) is counted under a(27).
Crossrefs
Programs
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Mathematica
normQ[m_]:=Or[m=={},Union[m]==Range[Max[m]]]; Table[Length[Select[IntegerPartitions[n],normQ[Length/@Split[Sort[Length/@Split[#]]]]&]],{n,0,30}]
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