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Revision History for A359906

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Number of integer partitions of n with integer mean and integer median.
(history; published version)
#6 by Michael De Vlieger at Sun Jan 22 09:15:15 EST 2023
STATUS

proposed

approved

#5 by Gus Wiseman at Sun Jan 22 08:26:19 EST 2023
STATUS

editing

proposed

#4 by Gus Wiseman at Sun Jan 22 08:25:58 EST 2023
COMMENTS

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

MATHEMATICA

Table[Length[Select[IntegerPartitions[n], IntegerQ[Mean[#]]&&IntegerQ[Median[#]]&]], {n, 1, 30}]

CROSSREFS

A008284/A058398/A327482 count counts partitions by mean, see also A008284, A327482.

A237984 counts partitions containing their mean, strict A240850, ranked by A327473.

A359893/A359901/A359902 count partitions by median, ranked by A360005.

A360005(n)/2 gives median of prime indices.

Cf. A000016, A082550, A237984, A240219, `A316313, A326669, A327475, A349156, `A359889, A359894, A359897, A359905.

#3 by Gus Wiseman at Sun Jan 22 00:06:26 EST 2023
COMMENTS

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

#2 by Gus Wiseman at Sat Jan 21 21:09:28 EST 2023
NAME

allocated for Gus WisemanNumber of integer partitions of n with integer mean and integer median.

DATA

1, 2, 2, 4, 2, 8, 2, 10, 9, 14, 2, 39, 2, 24, 51, 49, 2, 109, 2, 170, 144, 69, 2, 455, 194, 116, 381, 668, 2, 1378, 2, 985, 956, 316, 2043, 4328, 2, 511, 2293, 6656, 2, 8634, 2, 8062, 14671, 1280, 2, 26228, 8035, 15991, 11614, 25055, 2, 47201, 39810, 65092

OFFSET

1,2

EXAMPLE

The a(1) = 1 through a(9) = 9 partitions:

1 2 3 4 5 6 7 8 9

11 111 22 11111 33 1111111 44 333

31 42 53 432

1111 51 62 441

222 71 522

321 2222 531

411 3221 621

111111 3311 711

5111 111111111

11111111

MATHEMATICA

Table[Length[Select[IntegerPartitions[n], IntegerQ[Mean[#]]&&IntegerQ[Median[#]]&]], {n, 1, 30}]

CROSSREFS

For just integer mean we have A067538, strict A102627, ranked by A316413.

For just integer median we have A325347, strict A359907, ranked by A359908.

These partitions are ranked by A360009.

A000041 counts partitions, strict A000009.

A008284/A058398/A327482 count partitions by mean.

A051293 counts subsets with integer mean, median A000975.

A237984 counts partitions containing their mean, strict A240850, ranked by A327473.

A326567/A326568 gives mean of prime indices.

A326622 counts factorizations with integer mean, strict A328966.

A359893/A359901/A359902 count partitions by median, ranked by A360005.

Cf. A000016, A082550, A240219, `A316313, A326669, A327475, A349156, `A359889, A359894, A359897, A359905.

KEYWORD

allocated

nonn

AUTHOR

Gus Wiseman, Jan 21 2023

STATUS

approved

editing

#1 by Gus Wiseman at Tue Jan 17 23:19:16 EST 2023
NAME

allocated for Gus Wiseman

KEYWORD

allocated

STATUS

approved