OFFSET
0,4
COMMENTS
First differs from A275972 in counting (7,5,3,1), which is not knapsack.
EXAMPLE
The partition y = (7,5,3,1) has no subset with sum in y, so is counted under a(16).
The partition y = (15,8,4,2,1) has subset {1,2,4,8} with sum in y, so is not counted under a(31).
The a(1) = 1 through a(9) = 8 partitions:
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(2,1) (3,1) (3,2) (4,2) (4,3) (5,3) (5,4)
(4,1) (5,1) (5,2) (6,2) (6,3)
(6,1) (7,1) (7,2)
(4,2,1) (5,2,1) (8,1)
(4,3,2)
(5,3,1)
(6,2,1)
MATHEMATICA
Table[Length[Select[IntegerPartitions[n], Function[ptn, UnsameQ@@ptn&&Select[Subsets[ptn, {2, Length[ptn]}], MemberQ[ptn, Total[#]]&]=={}]]], {n, 0, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jul 29 2023
STATUS
approved