OFFSET
1,1
COMMENTS
EXAMPLE
The sequence of terms together with their prime indices begins:
5: {3}
7: {4}
9: {2,2}
11: {5}
13: {6}
14: {1,4}
15: {2,3}
17: {7}
19: {8}
21: {2,4}
22: {1,5}
23: {9}
25: {3,3}
26: {1,6}
27: {2,2,2}
29: {10}
31: {11}
33: {2,5}
34: {1,7}
35: {3,4}
MATHEMATICA
Select[Range[100], DivisorSigma[0, #]<Total[Cases[FactorInteger[#], {p_, k_}:>PrimePi[p]*k]]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 23 2019
STATUS
approved