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A324754
Number of integer partitions of n containing no part > 1 whose prime indices all belong to the partition.
8
1, 1, 2, 2, 4, 3, 7, 8, 11, 12, 19, 19, 30, 34, 46, 50, 71, 76, 104, 119, 151, 171, 225, 247, 315, 360, 446, 504, 629, 703, 867, 986, 1192, 1346, 1636, 1837, 2204, 2500, 2965, 3348, 3980, 4475, 5276, 5963, 6973, 7852, 9194, 10335, 12009, 13536, 15650, 17589
OFFSET
0,3
COMMENTS
A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
For example, (6,2) is such a partition because the prime indices of 6 are {1,2}, which do not all belong to the partition. On the other hand, (5,3) is not such a partition because the prime indices of 5 are {3}, and 3 belongs to the partition.
EXAMPLE
The a(1) = 1 through a(8) = 11 integer partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (111) (22) (311) (33) (43) (44)
(31) (11111) (42) (52) (62)
(1111) (51) (61) (71)
(222) (331) (422)
(3111) (511) (611)
(111111) (31111) (2222)
(1111111) (3311)
(5111)
(311111)
(11111111)
MATHEMATICA
Table[Length[Select[IntegerPartitions[n], !MemberQ[#, k_/; SubsetQ[#, PrimePi/@First/@FactorInteger[k]]]&]], {n, 0, 30}]
CROSSREFS
The subset version is A324738, with maximal case A324744. The strict case is A324749. The Heinz number version is A324759. An infinite version is A324694.
Sequence in context: A283502 A324756 A373516 * A174220 A334871 A048675
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 16 2019
STATUS
approved