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A360455 Number of integer partitions of n for which the distinct parts have the same median as the multiplicities. 7

%I #8 Feb 11 2023 08:12:56

%S 1,1,0,0,2,1,1,0,2,2,5,8,10,14,20,19,26,31,35,41,55,65,85,102,118,151,

%T 181,201,236,281,313,365,424,495,593,688,825,978,1181,1374,1650,1948,

%U 2323,2682,3175,3680,4314,4930,5718,6546,7532,8557,9777,11067,12622

%N Number of integer partitions of n for which the distinct parts have the same median as the multiplicities.

%C The median of a multiset is either the middle part (for odd length), or the average of the two middle parts (for even length).

%e The a(1) = 1 through a(11) = 8 partitions:

%e 1 . . 22 221 3111 . 3311 333 3331 32222

%e 211 41111 32211 33211 33221

%e 42211 44111

%e 322111 52211

%e 511111 322211

%e 332111

%e 422111

%e 3221111

%t Table[Length[Select[IntegerPartitions[n], Median[Length/@Split[#]]==Median[Union[#]]&]],{n,0,30}]

%Y For mean instead of median: A114638, ranks A324570.

%Y For parts instead of multiplicities: A360245, ranks A360249.

%Y These partitions have ranks A360453.

%Y For parts instead of distinct parts: A360456, ranks A360454.

%Y A000041 counts integer partitions, strict A000009.

%Y A116608 counts partitions by number of distinct parts.

%Y A325347 counts partitions w/ integer median, strict A359907, ranks A359908.

%Y A359893 and A359901 count partitions by median, odd-length A359902.

%Y Cf. A000975, A027193, A240219, A326619/A326620, A359894, A359895, A360068, A360243, A360244, A360248.

%K nonn

%O 0,5

%A _Gus Wiseman_, Feb 10 2023

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Last modified September 16 23:59 EDT 2024. Contains 375984 sequences. (Running on oeis4.)