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A323586
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Number of plane partitions of n with no repeated rows (or, equivalently, no repeated columns).
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0
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1, 1, 2, 5, 8, 16, 30, 53, 89, 158, 265, 443, 735, 1197
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OFFSET
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0,3
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LINKS
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EXAMPLE
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The a(4) = 8 plane partitions with no repeated rows:
4 31 22 211 1111
.
3 21 111
1 1 1
The a(6) = 30 plane partitions with no repeated columns:
6 51 42 321
.
5 4 41 3 31 32 31 22 21 221 211
1 2 1 3 2 1 11 2 21 1 11
.
4 3 31 2 21 22 21 111
1 2 1 2 2 1 11 11
1 1 1 2 1 1 1 1
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3 2 21 11
1 2 1 11
1 1 1 1
1 1 1 1
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2 11
1 1
1 1
1 1
1 1
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1
1
1
1
1
1
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MATHEMATICA
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primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
facs[n_]:=If[n<=1, {{}}, Join@@Table[Map[Prepend[#, d]&, Select[facs[n/d], Min@@#>=d&]], {d, Rest[Divisors[n]]}]];
ptnplane[n_]:=Union[Map[Reverse@*primeMS, Join@@Permutations/@facs[n], {2}]];
Table[Sum[Length[Select[ptnplane[Times@@Prime/@y], And[UnsameQ@@#, And@@GreaterEqual@@@#, And@@(GreaterEqual@@@Transpose[PadRight[#]])]&]], {y, IntegerPartitions[n]}], {n, 10}]
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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