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A323435
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Number of rectangular plane partitions of n with no repeated rows or columns.
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4
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1, 1, 1, 3, 3, 6, 8, 13, 15, 28, 33, 52, 69, 101, 133, 202, 256, 369, 506, 688, 935, 1295, 1736, 2355, 3184, 4284, 5745, 7722, 10281, 13691, 18316, 24168, 32058, 42389, 55915, 73542, 96753, 126709, 166079, 217017, 283258
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OFFSET
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0,4
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COMMENTS
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Number of ways to fill a (not necessarily square) matrix with the parts of an integer partition of n so that the rows and columns are weakly decreasing and with no repeated rows or columns.
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LINKS
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EXAMPLE
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The a(7) = 13 plane partitions:
[7] [4 3] [5 2] [6 1] [4 2 1]
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[6] [5] [3 2] [4 1] [4] [2 2] [3 1]
[1] [2] [1 1] [1 1] [3] [2 1] [2 1]
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[4]
[2]
[1]
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MATHEMATICA
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Table[Sum[Length[Select[Union[Tuples[IntegerPartitions[#, {k}]&/@ptn]], And[UnsameQ@@#, UnsameQ@@Transpose[#], And@@(OrderedQ[#, GreaterEqual]&/@Transpose[#])]&]], {ptn, IntegerPartitions[n]}, {k, Min[ptn]}], {n, 20}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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