OFFSET
0,5
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.
EXAMPLE
The a(0) = 1 through a(10) = 6 strict integer partitions:
() (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
(3,1) (4,2) (4,3) (6,2) (5,4) (6,4)
(5,1) (5,2) (7,1) (6,3) (7,3)
(6,1) (7,2) (8,2)
(9,1)
(6,3,1)
MATHEMATICA
Table[Length[Select[IntegerPartitions[n], UnsameQ@@#&&!MemberQ[#, k_/; SubsetQ[#, PrimePi/@First/@FactorInteger[k]]]&]], {n, 0, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 15 2019
STATUS
approved