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A327472 Number of integer partitions of n not containing their mean. 48

%I #8 Sep 22 2023 01:58:47

%S 1,0,0,1,2,5,6,13,16,25,34,54,56,99,121,154,201,295,324,488,541,725,

%T 957,1253,1292,1892,2356,2813,3378,4563,4838,6840,7686,9600,12076,

%U 14180,15445,21635,25627,29790,33309,44581,48486,63259,70699,82102,104553,124752

%N Number of integer partitions of n not containing their mean.

%e The a(3) = 1 through a(8) = 16 partitions not containing their mean:

%e (21) (31) (32) (42) (43) (53)

%e (211) (41) (51) (52) (62)

%e (221) (411) (61) (71)

%e (311) (2211) (322) (332)

%e (2111) (3111) (331) (422)

%e (21111) (421) (431)

%e (511) (521)

%e (2221) (611)

%e (3211) (3311)

%e (4111) (5111)

%e (22111) (22211)

%e (31111) (32111)

%e (211111) (41111)

%e (221111)

%e (311111)

%e (2111111)

%t Table[Length[Select[IntegerPartitions[n],!MemberQ[#,Mean[#]]&]],{n,0,20}]

%o (Python)

%o from sympy.utilities.iterables import partitions

%o def A327472(n): return sum(1 for s,p in partitions(n,size=True) if n%s or n//s not in p) if n else 1 # _Chai Wah Wu_, Sep 21 2023

%Y The Heinz numbers of these partitions are A327476.

%Y Partitions with their mean are A237984.

%Y Subsets without their mean are A327471.

%Y Subsets with n but without their mean are A327477.

%Y Strict partitions without their mean are A240851.

%Y Cf. A007865, A067538, A067538, A102627, A114639, A324756, A327473.

%K nonn

%O 0,5

%A _Gus Wiseman_, Sep 13 2019

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)