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 terms together with their prime indices begins:
42: {1,2,4}
84: {1,1,2,4}
126: {1,2,2,4}
168: {1,1,1,2,4}
210: {1,2,3,4}
230: {1,3,9}
252: {1,1,2,2,4}
294: {1,2,4,4}
336: {1,1,1,1,2,4}
378: {1,2,2,2,4}
390: {1,2,3,6}
399: {2,4,8}
420: {1,1,2,3,4}
460: {1,1,3,9}
462: {1,2,4,5}
504: {1,1,1,2,2,4}
546: {1,2,4,6}
588: {1,1,2,4,4}
630: {1,2,2,3,4}
672: {1,1,1,1,1,2,4}
MATHEMATICA
Select[Range[1000], !UnsameQ@@Divide@@@Subsets[PrimePi/@First/@FactorInteger[#], {2}]&]
CROSSREFS
The subset case is A325860.
The maximal case is A325861.
The integer partition case is A325853.
The strict integer partition case is A325854.
Heinz numbers of the counterexamples are given by A325994.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jun 02 2019
STATUS
approved