A363946 - OEIS

A363946

Triangle read by rows where T(n,k) is the number of integer partitions of n with high mean k.

1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 3, 0, 1, 0, 1, 3, 2, 0, 1, 0, 1, 6, 3, 0, 0, 1, 0, 1, 6, 4, 3, 0, 0, 1, 0, 1, 11, 5, 4, 0, 0, 0, 1, 0, 1, 11, 13, 0, 4, 0, 0, 0, 1, 0, 1, 18, 9, 8, 5, 0, 0, 0, 0, 1, 0, 1, 18, 21, 10, 0, 5, 0, 0, 0, 0, 1

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OFFSET

0,13

COMMENTS

Extending the terminology of A124944, the "high mean" of a multiset is obtained by taking the mean and rounding up.

LINKS

Table of n, a(n) for n=0..77.

EXAMPLE

Triangle begins:

0 1

0 1 1

0 1 1 1

0 1 3 0 1

0 1 3 2 0 1

0 1 6 3 0 0 1

0 1 6 4 3 0 0 1

0 1 11 5 4 0 0 0 1

0 1 11 13 0 4 0 0 0 1

0 1 18 9 8 5 0 0 0 0 1

0 1 18 21 10 0 5 0 0 0 0 1

0 1 29 28 12 0 6 0 0 0 0 0 1

0 1 29 32 18 14 0 6 0 0 0 0 0 1

0 1 44 43 23 16 0 7 0 0 0 0 0 0 1

0 1 44 77 27 19 0 0 7 0 0 0 0 0 0 1

Row n = 7 counts the following partitions:

. (1111111) (4111) (511) (61) . . (7)

(3211) (421) (52)

(31111) (331) (43)

(2221) (322)

(22111)

(211111)

MATHEMATICA

meanup[y_]:=If[Length[y]==0, 0, Ceiling[Mean[y]]];

Table[Length[Select[IntegerPartitions[n], meanup[#]==k&]], {n, 0, 15}, {k, 0, n}]

CROSSREFS

Row sums are A000041.

Column k = 2 is A026905 redoubled, ranks A363950.

For median instead of mean we have triangle A124944, low A124943.

For mode instead of mean we have rank stat A363486, high A363487.

For median instead of mean we have rank statistic A363942, low A363941.

The rank statistic for this triangle is A363944.

The version for low mean is A363945, rank statistic A363943.

For mode instead of mean we have triangle A363953, low A363952.

A008284 counts partitions by length, A058398 by mean.

A051293 counts subsets with integer mean, median A000975.

A067538 counts partitions with integer mean, strict A102627, ranks A316413.

A349156 counts partitions with non-integer mean, ranks A348551.

Cf. A002865, A025065, A237984, A327472, A327482, A344296, A362612, A363723, A363724, A363731, A363948.

Sequence in context: A293305 A316896 A230626 * A354824 A183700 A275478

Adjacent sequences: A363943 A363944 A363945 * A363947 A363948 A363949

KEYWORD

nonn,tabl

AUTHOR

Gus Wiseman, Jun 30 2023

STATUS

approved