OFFSET
1,3
COMMENTS
For an integer partition y of n, we call a positive integer k <= n a non-subset-sum iff there is no submultiset of y summing to k.
EXAMPLE
The a(6) = 19 ways, showing each partition and its non-subset-sums:
(6): 1,2,3,4,5
(51): 2,3,4
(42): 1,3,5
(411): 3
(33): 1,2,4,5
(321):
(3111):
(222): 1,3,5
(2211):
(21111):
(111111):
MATHEMATICA
Table[Total[Length[Complement[Range[n], Total/@Subsets[#]]]&/@IntegerPartitions[n]], {n, 10}]
PROG
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 23 2023
EXTENSIONS
a(21)-a(45) from Chai Wah Wu, Sep 25 2023
STATUS
approved