OFFSET
1,1
COMMENTS
The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).
EXAMPLE
The sequence of strict integer partitions with Heinz numbers in the sequence begins: (1), (15,10,6), (21,14,6), (20,15,6), (15,12,10), (45,10,6), (18,15,10).
MATHEMATICA
Select[Range[100000], With[{m=PrimePi/@FactorInteger[#][[All, 1]]}, And[SquareFreeQ[#], GCD@@m==1, And@@(GCD[##]>1&)@@@Select[Tuples[m, 2], Less@@#&]]]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 02 2018
STATUS
approved