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A322529 Number of integer partitions of n whose parts all have the same number of prime factors (counted with or without multiplicity) and whose product of parts is a squarefree number. 4

%I #16 Aug 17 2024 03:20:47

%S 1,1,2,2,1,3,2,3,2,2,4,2,3,3,4,4,4,3,5,4,5,6,6,6,6,6,8,6,7,9,8,11,8,

%T 11,11,11,12,13,13,15,13,17,17,18,18,17,20,22,21,24,24,24,26,29,28,33,

%U 30,35,34,38,38,45,42,43,45,48,52,54,55,59,59,65,65,72,73

%N Number of integer partitions of n whose parts all have the same number of prime factors (counted with or without multiplicity) and whose product of parts is a squarefree number.

%C Such a partition must be strict (unless it is all 1's) and its parts must also be squarefree.

%H Lucas A. Brown, <a href="/A322529/b322529.txt">Table of n, a(n) for n = 0..133</a>

%H Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A322529.py">Python program</a>.

%e The a(30) = 8 integer partitions:

%e (30),

%e (17,13),(19,11),(23,7),

%e (17,11,2),(23,5,2),

%e (13,7,5,3,2),

%e (1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1).

%t Table[Length[Select[IntegerPartitions[n],And[SameQ@@PrimeOmega/@#,SquareFreeQ[Times@@#]]&]],{n,30}]

%Y Cf. A002865, A003963, A005117, A038041, A064573, A073576, A302505, A319056, A320322, A321717, A321718, A322526, A322527, A322528, A322530, A322531.

%K nonn

%O 0,3

%A _Gus Wiseman_, Dec 14 2018

%E a(51)-a(69) from _Jinyuan Wang_, Jun 27 2020

%E a(70) onwards from _Lucas A. Brown_, Aug 17 2024

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Last modified September 9 05:33 EDT 2024. Contains 375759 sequences. (Running on oeis4.)