OFFSET
1,2
COMMENTS
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
3: {2}
7: {4}
9: {2,2}
11: {5}
13: {6}
19: {8}
21: {2,4}
27: {2,2,2}
29: {10}
33: {2,5}
37: {12}
39: {2,6}
43: {14}
47: {15}
49: {4,4}
53: {16}
57: {2,8}
59: {17}
61: {18}
63: {2,2,4}
MATHEMATICA
aQ[n_]:=And@@Cases[If[n==1, {}, FactorInteger[n]], {p_, k_}:>!aQ[PrimePi[p]]];
Select[Range[100], aQ]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 10 2019
STATUS
approved