OFFSET
1,2
COMMENTS
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
3: {2}
6: {1,2}
7: {4}
9: {2,2}
11: {5}
12: {1,1,2}
14: {1,4}
15: {2,3}
18: {1,2,2}
19: {8}
21: {2,4}
22: {1,5}
24: {1,1,1,2}
27: {2,2,2}
28: {1,1,4}
29: {10}
30: {1,2,3}
33: {2,5}
35: {3,4}
36: {1,1,2,2}
MATHEMATICA
aQ[n_]:=n==1||Or@@Cases[FactorInteger[n], {p_, k_}:>!aQ[PrimePi[p]]];
Select[Range[100], aQ]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 10 2019
STATUS
approved