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 A316981 Number of non-isomorphic strict multiset partitions of weight n with no equivalent vertices. 5
 1, 1, 2, 6, 15, 40, 121 (list; graph; refs; listen; history; text; internal format)
 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 EXAMPLE Non-isomorphic 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

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Last modified January 22 10:25 EST 2020. Contains 331144 sequences. (Running on oeis4.)