OFFSET
0,3
EXAMPLE
The partition (10,5,3,3,2,1) has nonzero differences (5,2,1,1) so is counted under a(24).
The a(1) = 1 through a(9) = 13 partitions:
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(11) (21) (22) (221) (33) (421) (44) (63)
(111) (211) (2111) (42) (2221) (422) (333)
(1111) (11111) (222) (3211) (2222) (3321)
(321) (22111) (3221) (4221)
(2211) (211111) (4211) (22221)
(21111) (1111111) (22211) (32211)
(111111) (32111) (42111)
(221111) (222111)
(2111111) (321111)
(11111111) (2211111)
(21111111)
(111111111)
MATHEMATICA
Table[Length[Select[IntegerPartitions[n], SubsetQ[#, Differences[Union[#]]]&]], {n, 0, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Aug 04 2023
STATUS
approved