OFFSET
1,1
COMMENTS
The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.
EXAMPLE
The terms together with their prime indices begin:
3: (2) 30: (3,2,1) 54: (2,2,2,1)
5: (3) 31: (11) 55: (5,3)
7: (4) 33: (5,2) 57: (8,2)
9: (2,2) 35: (4,3) 59: (17)
11: (5) 37: (12) 61: (18)
13: (6) 39: (6,2) 63: (4,2,2)
15: (3,2) 41: (13) 65: (6,3)
17: (7) 42: (4,2,1) 66: (5,2,1)
18: (2,2,1) 43: (14) 67: (19)
19: (8) 45: (3,2,2) 69: (9,2)
21: (4,2) 47: (15) 70: (4,3,1)
23: (9) 49: (4,4) 71: (20)
25: (3,3) 50: (3,3,1) 73: (21)
27: (2,2,2) 51: (7,2) 75: (3,3,2)
29: (10) 53: (16) 77: (5,4)
MATHEMATICA
ck[y_]:=With[{w=Count[y, 1]}, If[w==0, Max@@y, Count[y, _?(#>w&)]-w]];
Select[Range[100], ck[Reverse[Flatten[Cases[FactorInteger[#], {p_, k_}:>Table[PrimePi[p], {k}]]]]]>0&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 09 2022
STATUS
approved