

A316981


Number of nonisomorphic strict multiset partitions of weight n with no equivalent vertices.


5




OFFSET

0,3


COMMENTS

Also the number of nonnegative integer n X n matrices with sum of elements equal to n, under row and column permutations, with no equal rows and no equal columns.
In a multiset partition, two vertices are equivalent if in every block the multiplicity of the first is equal to the multiplicity of the second.


LINKS

Table of n, a(n) for n=0..6.


EXAMPLE

Nonisomorphic representatives of the a(3) = 6 strict multiset partitions with no equivalent vertices (first column) and their duals (second column):
(111) <> (111)
(122) <> (1)(11)
(1)(11) <> (122)
(1)(22) <> (1)(22)
(2)(12) <> (2)(12)
(1)(2)(3) <> (1)(2)(3)


CROSSREFS

Cf. A000009, A001055, A007716, A007717, A020555, A045778.
Cf. A316974, A316978, A316979, A316980, A316983.
Sequence in context: A001654 A062106 A206000 * A319560 A061322 A004664
Adjacent sequences: A316978 A316979 A316980 * A316982 A316983 A316984


KEYWORD

nonn,more


AUTHOR

Gus Wiseman, Jul 18 2018


STATUS

approved



