OFFSET
0,7
COMMENTS
The Heinz numbers of these partitions are given by A054744.
FORMULA
G.f.: Product_{k>=1} (1 + x^(prime(k)*k) / (1 - x^k)). - Ilya Gutkovskiy, Nov 28 2020
EXAMPLE
The first few terms count the following integer partitions:
0: ()
2: (11)
3: (111)
4: (1111)
5: (11111)
6: (222)
6: (111111)
7: (1111111)
8: (2222)
8: (22211)
8: (11111111)
9: (222111)
9: (111111111)
10: (22222)
10: (222211)
10: (2221111)
10: (1111111111)
11: (2222111)
11: (22211111)
11: (11111111111)
12: (222222)
12: (2222211)
12: (22221111)
12: (222111111)
12: (111111111111)
MATHEMATICA
Table[Length[Select[IntegerPartitions[n], And@@Table[Count[#, i]>=Prime[i], {i, Union[#]}]&]], {n, 0, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 01 2019
STATUS
approved