OFFSET
1,1
COMMENTS
A prime index of n is a number m such that prime(m) divides n.
EXAMPLE
The sequence of integer partitions whose Heinz numbers are in the sequence begins: (22), (33), (222), (44), (2222), (55), (333), (66), (22222), (77), (444), (88), (4422), (99), (3333), (222222).
MATHEMATICA
Select[Range[10000], With[{t=Transpose[FactorInteger[#]]}, And[GCD@@PrimePi/@t[[1]]>1, GCD@@t[[2]]>1]]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 12 2018
STATUS
approved