OFFSET
1,21
COMMENTS
An integer partition is knapsack if every distinct submultiset has a different sum.
The Heinz numbers of these partitions are given by A326018.
EXAMPLE
The initial terms count the following partitions:
15: (5,4,3,3)
21: (7,6,5,3)
21: (7,5,3,3,3)
24: (8,7,6,3)
25: (7,5,5,4,4)
27: (9,8,7,3)
27: (9,7,6,5)
27: (8,7,3,3,3,3)
31: (10,8,6,6,1)
33: (11,9,7,3,3)
33: (11,8,5,5,4)
33: (11,7,6,6,3)
33: (11,7,3,3,3,3,3)
33: (11,5,5,4,4,4)
33: (10,9,8,3,3)
33: (10,8,6,6,3)
33: (10,8,3,3,3,3,3)
MATHEMATICA
sums[ptn_]:=sums[ptn]=If[Length[ptn]==1, ptn, Union@@(Join[sums[#], sums[#]+Total[ptn]-Total[#]]&/@Union[Table[Delete[ptn, i], {i, Length[ptn]}]])];
ksQ[y_]:=Length[sums[Sort[y]]]==Times@@(Length/@Split[Sort[y]]+1)-1;
maxks[n_]:=Select[IntegerPartitions[n], ksQ[#]&&Select[Table[Sort[Append[#, i]], {i, Range[Max@@#]}], ksQ]=={}&];
Table[Length[maxks[n]], {n, 30}]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Jun 03 2019
STATUS
approved