OFFSET
1,1
COMMENTS
FORMULA
a(n) = A324703(n) - 1.
EXAMPLE
The sequence of terms together with their prime indices begins:
2: {1}
5: {3}
13: {6}
25: {3,3}
43: {14}
65: {3,6}
101: {26}
125: {3,3,3}
169: {6,6}
193: {44}
215: {3,14}
317: {66}
325: {3,3,6}
505: {3,26}
557: {102}
559: {6,14}
625: {3,3,3,3}
701: {126}
845: {3,6,6}
965: {3,44}
MATHEMATICA
aQ[n_]:=Switch[n, 0, False, 1, False, 2, True, _, And@@Cases[FactorInteger[n], {p_, k_}:>aQ[PrimePi[p]-1]]];
Select[Range[100], aQ]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 11 2019
STATUS
approved