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 terms together with their prime indices begin:
3: {2}
14: {1,4}
21: {2,4}
35: {3,4}
49: {4,4}
52: {1,1,6}
78: {1,2,6}
117: {2,2,6}
130: {1,3,6}
152: {1,1,1,8}
182: {1,4,6}
195: {2,3,6}
228: {1,1,2,8}
273: {2,4,6}
286: {1,5,6}
325: {3,3,6}
338: {1,6,6}
342: {1,2,2,8}
MATHEMATICA
Select[Range[2, 100], PrimePi[FactorInteger[#][[-1, 1]]]==2*PrimeOmega[#]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 05 2023
STATUS
approved