OFFSET
1,2
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
3: {2}
5: {3}
6: {1,2}
7: {4}
10: {1,3}
11: {5}
13: {6}
14: {1,4}
15: {2,3}
17: {7}
19: {8}
21: {2,4}
22: {1,5}
23: {9}
24: {1,1,1,2}
26: {1,6}
29: {10}
31: {11}
MATHEMATICA
Select[Range[30], MemberQ[Table[Sort[Last/@FactorInteger[k!]], {k, #}], Sort[Last/@FactorInteger[#]]]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 08 2019
STATUS
approved