OFFSET
1,1
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 initial terms, prime indices, and means:
2: {1} -> 1
4: {1,1} -> 1
8: {1,1,1} -> 1
12: {1,1,2} -> 4/3
16: {1,1,1,1} -> 1
24: {1,1,1,2} -> 5/4
32: {1,1,1,1,1} -> 1
48: {1,1,1,1,2} -> 6/5
64: {1,1,1,1,1,1} -> 1
72: {1,1,1,2,2} -> 7/5
80: {1,1,1,1,3} -> 7/5
96: {1,1,1,1,1,2} -> 7/6
MATHEMATICA
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Select[Range[100], Mean[prix[#]]<3/2&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jul 02 2023
STATUS
approved