OFFSET
1,2
COMMENTS
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
6: {1,2}
9: {2,2}
10: {1,3}
12: {1,1,2}
14: {1,4}
18: {1,2,2}
22: {1,5}
26: {1,6}
30: {1,2,3}
34: {1,7}
36: {1,1,2,2}
38: {1,8}
40: {1,1,1,3}
42: {1,2,4}
46: {1,9}
58: {1,10}
60: {1,1,2,3}
62: {1,11}
MATHEMATICA
Select[Range[100], #==1||SubsetQ[PrimePi/@First/@FactorInteger[#], Last/@FactorInteger[#]]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 18 2019
STATUS
approved