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A358837
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Number of odd-length multiset partitions of integer partitions of n.
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3
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0, 1, 2, 4, 7, 14, 28, 54, 106, 208, 399, 757, 1424, 2642, 4860, 8851, 15991, 28673, 51095, 90454, 159306, 279067, 486598, 844514, 1459625, 2512227, 4307409, 7357347, 12522304, 21238683, 35903463, 60497684, 101625958, 170202949, 284238857, 473356564, 786196353
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OFFSET
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0,3
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LINKS
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FORMULA
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EXAMPLE
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The a(1) = 1 through a(5) = 14 multiset partitions:
{{1}} {{2}} {{3}} {{4}} {{5}}
{{1,1}} {{1,2}} {{1,3}} {{1,4}}
{{1,1,1}} {{2,2}} {{2,3}}
{{1},{1},{1}} {{1,1,2}} {{1,1,3}}
{{1,1,1,1}} {{1,2,2}}
{{1},{1},{2}} {{1,1,1,2}}
{{1},{1},{1,1}} {{1,1,1,1,1}}
{{1},{1},{3}}
{{1},{2},{2}}
{{1},{1},{1,2}}
{{1},{2},{1,1}}
{{1},{1},{1,1,1}}
{{1},{1,1},{1,1}}
{{1},{1},{1},{1},{1}}
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MATHEMATICA
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sps[{}]:={{}}; sps[set:{i_, ___}]:=Join@@Function[s, Prepend[#, s]&/@sps[Complement[set, s]]]/@Cases[Subsets[set], {i, ___}];
mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]];
Table[Length[Select[Join@@mps/@Reverse/@IntegerPartitions[n], OddQ[Length[#]]&]], {n, 0, 10}]
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PROG
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(PARI)
P(v, y) = {1/prod(k=1, #v, (1 - y*x^k + O(x*x^#v))^v[k])}
seq(n) = {my(v=vector(n, k, numbpart(k))); (Vec(P(v, 1)) - Vec(P(v, -1)))/2} \\ Andrew Howroyd, Dec 31 2022
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CROSSREFS
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The version for set partitions is A024429.
These multiset partitions are ranked by A026424.
The version for partitions is A027193.
The version for twice-partitions is A358824.
A001970 counts multiset partitions of integer partitions.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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