A325132 Number of integer partitions of n where the multiplicity of each part k is at least prime(k).
1, 0, 1, 1, 1, 1, 2, 1, 3, 2, 4, 3, 5, 4, 6, 6, 7, 7, 10, 8, 11, 12, 12, 14, 17, 16, 20, 22, 24, 26, 31, 31, 37, 39, 43, 46, 54, 53, 63, 65, 73, 75, 87, 87, 100, 102, 115, 117, 133, 134, 151, 155, 172, 176, 197, 202, 223, 231, 254, 262, 290, 298, 327, 341, 370
Offset: 0
Keywords
Examples
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)
Programs
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Mathematica
Table[Length[Select[IntegerPartitions[n],And@@Table[Count[#,i]>=Prime[i],{i,Union[#]}]&]],{n,0,30}]
Formula
G.f.: Product_{k>=1} (1 + x^(prime(k)*k) / (1 - x^k)). - Ilya Gutkovskiy, Nov 28 2020
Comments